Add 'flashcards' as separate session feature

src/main/java/de/thm/arsnova/entities/SessionFeature.java

@@ -44,6 +44,7 @@ public class SessionFeature implements Serializable {
 	private boolean interposed = true;
 	private boolean pi = true;
 	private boolean learningProgress = true;
+	private boolean flashcardFeature = true;
 	private boolean slides = false;
 
 	public SessionFeature(SessionFeature features) {
@@ -56,6 +57,7 @@ public class SessionFeature implements Serializable {
 			this.liveFeedback = features.liveFeedback;
 			this.interposedFeedback = features.interposedFeedback;
 			this.liveClicker = features.liveClicker;
+			this.flashcardFeature = features.flashcardFeature;
 			this.flashcard = features.flashcard;
 			this.total = features.total;
 			this.lecture = features.lecture;
@@ -147,6 +149,14 @@ public class SessionFeature implements Serializable {
 		this.peerGrading = peerGrading;
 	}
 
+	public boolean isFlashcardFeature() {
+		return flashcardFeature;
+	}
+
+	public void setFlashcardFeature(boolean flashcardFeature) {
+		this.flashcardFeature = flashcardFeature;
+	}
+
 	public boolean isFlashcard() {
 		return flashcard;
 	}