Bug was introduced in 0d050f02.

Presenter now starts a proxy server to the backend API on its own.

Updated copyright year and adjusted header format to be consistent over
all files and with other ARSnova projects.

preperation questions. Task #14343

Conflicts:
	pom.xml
	src/main/resources/log4j.properties

This updates Spring, Netty-socketio and additional libraries to their
latest patch releases.

Use JaCoCo instead of Cobertura and remove obsolete Sunfire excludes.

#14099

See 8eaff73a.

Conflicts:
	pom.xml

This updates Spring, Logging and Netty-socketio. The new Netty-socketio
version fixes memory leaks and disables SSL3 encryption (POODLE
vulnerability).