Fix compiler errors in Qt 5.2.1
Fix compiler errors, replace phonon with QtMultimedia
Merge branch 'feature/qt5-migration' into feature/object-save-loader

Conflicts:
	src/external/win32/win32.cpp
	src/graphics/vector/gradient.cpp
	src/interface/editor.cpp
	src/interface/editor.h
	src/interface/mainwindow2.cpp
	src/structure/layersound.h