Update/Fix of PlayerService when using one or several musics via AddToPlaylistCommand, remote files were not downloaded

UI may use PlayIncomingMusicCommand to play only one music (and also clear playlist, ie. at double-clic on any music in app)
If user select several musics and use a button to push them to playlist, then we must use AddToPlaylistCommand
Merge branch 'master' of https://github.com/SharUTC/SharUTC.git
Fix ConnectionRequestCommand
Update connection test
Merge branch 'master' of https://github.com/SharUTC/SharUTC.git
Changed ActivePeerList (Peers -> UserInfos)(will see if we need to change the name). Biz'
Only hidden constructor call behind a method
Removed password from network messages, password musn't be stored without encryption
Playlist Javadoc
JUnit test passed for AddMusicToCategoryCommand + RemoveMusicFromCategoryCommand
Javadoc AddMusicToCategoryCommand
Merge branch 'master' into ui

Conflicts:
	nbproject/project.properties
	src/fr/utc/lo23/sharutc/controler/command/player/AddToPlaylistCommandImpl.java
	src/fr/utc/lo23/sharutc/controler/command/player/RemoveFromPlaylistCommandImpl.java