Correction of the segmentation fault that always occured: argc must be given by reference accordig to http://stackoverflow.com/questions/22243674/segmentation-fault-when-qt-qapplication-created-with-new
Insert is now working
Merge branch 'unstable' to 'master' since it's now stable
Selection by director
Added getMoviesByDirector() and getDirectorById()
First version of selection by director done
Documentation of DatabaseManager and cleaning of the to big methods
added missing return
Added action for Tags button
Right click on movie to edit metadata
Improved movie's folders  addition, solves #24
List of movies folders path updates in the settings window, changed the default folter to /home
Added debug message and documentation on methods

	modified:   src/MainWindow.cpp
	modified:   src/MainWindow.cpp
	modified:   src/MetadataWindow.cpp
Rename some ddb column + add methods to construct tags and people around movies
added fields + btn for peoples, btn not connected
Added getter for QVector<People> and save data from MetadataWindow
Added an editable field for peoples in metadatawindow
Skeletton of methods created: just need to be filled =D
Beginning of the People functionalities.
Update DDB_SCHEMA.md