[PMG] let a question be link to a whole phase rather than a specific period of the phase

* MCQTabView: can handle an array of variable descriptor
* UnreadCount: idem
* PrintActionPlugin: idem
* PMG Pages: put questions in an array rather than just pointing the listdescriptor
Merge remote-tracking branch 'origin/master' into glassfish4

Conflicts:
	wegas-app/src/main/java/com/wegas/app/pdf/uicomponent/UIGameModel.java