Update copyright year and add missing file headers

src/main/java/de/thm/arsnova/cache/CacheBusterImpl.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team and Contributors
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/config/AppConfig.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team and Contributors
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/config/AppInitializer.java

+/*
+ * This file is part of ARSnova Backend.
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
+ *
+ * ARSnova Backend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ARSnova Backend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 package de.thm.arsnova.config;
 
 import org.springframework.web.filter.CharacterEncodingFilter;

src/main/java/de/thm/arsnova/config/PersistenceConfig.java

+/*
+ * This file is part of ARSnova Backend.
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
+ *
+ * ARSnova Backend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ARSnova Backend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 package de.thm.arsnova.config;
 
 import de.thm.arsnova.model.serialization.CouchDbObjectMapperFactory;

src/main/java/de/thm/arsnova/config/SecurityInitializer.java

+/*
+ * This file is part of ARSnova Backend.
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
+ *
+ * ARSnova Backend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ARSnova Backend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 package de.thm.arsnova.config;
 
 import org.springframework.security.web.context.AbstractSecurityWebApplicationInitializer;

src/main/java/de/thm/arsnova/controller/AbstractEntityController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/AnswerController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/AuthenticationController.java

+/*
+ * This file is part of ARSnova Backend.
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
+ *
+ * ARSnova Backend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ARSnova Backend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 package de.thm.arsnova.controller;
 
 import de.thm.arsnova.model.ClientAuthentication;

src/main/java/de/thm/arsnova/controller/ContentController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/RoomController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/UserController.java

+/*
+ * This file is part of ARSnova Backend.
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
+ *
+ * ARSnova Backend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ARSnova Backend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 package de.thm.arsnova.controller;
 
 import com.fasterxml.jackson.annotation.JsonView;

src/main/java/de/thm/arsnova/controller/v2/CommentController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team and Contributors
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/v2/ContentController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team and Contributors
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/v2/FeedbackController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team and Contributors
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/v2/LegacyController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team and Contributors
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/v2/MotdController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team and Contributors
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/v2/RoomController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team and Contributors
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/controller/v2/UserController.java

 /*
  * This file is part of ARSnova Backend.
- * Copyright (C) 2012-2018 The ARSnova Team and Contributors
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
  *
  * ARSnova Backend is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/main/java/de/thm/arsnova/event/AfterCreationEvent.java

+/*
+ * This file is part of ARSnova Backend.
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
+ *
+ * ARSnova Backend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ARSnova Backend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 package de.thm.arsnova.event;
 
 import de.thm.arsnova.model.Entity;

src/main/java/de/thm/arsnova/event/AfterDeletionEvent.java

+/*
+ * This file is part of ARSnova Backend.
+ * Copyright (C) 2012-2019 The ARSnova Team and Contributors
+ *
+ * ARSnova Backend is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ARSnova Backend is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 package de.thm.arsnova.event;
 
 import de.thm.arsnova.model.Entity;