misc changes to SongSearcher
created the MusicController class
changed the implementation of ApiMusicImpl to implement Singleton Pattern
finished the implementation of MusicController
commented the MusicController class
vue de barre de recherche
Merge LO23/master
Merge LO23/master
Merge LO23/master
Modification du model d'importsong pour respecter le pattern MVC.
Merge origin/master
Merge pull request #148 from hebergui/BRANCHE_import-song-correctino

[IHM] Modification du model d'importsong pour respecter le pattern MVC.
Merge https://github.com/LO23/BitMusic
Merge LO23/master
Merge LO23/master
changed method SongSearcher.searchSongsbyUser with call to the network ApiMusic
finalised implementation of SongSearcher, need to check some methods
added javadoc comment to instance variable
make SongSearcher instance variable private
Merge pull request #150 from amina196/master

[music] finalised implementation ApiMusic with Singleton Pattern, and implementation of SongSearcher