The QTranslator objects need to be stored as class attributes as
otherwise they are destroyed after the Application constructor is done
and translations won't work.
Remove the deactivated MacOS dependent code for reacting on Cocoa events
for file associations from main.cpp
Try to implement the same functionality by reacting on QFileOpenEvent in
the Application class.
Create a new subclass of the QApplication class and move most of the
code in the main function to the constructor of the new class. This
makes the code a bit more consistent in terms of object orientedness,
makes it a little simpler and allows extending the new Application class
in the future.
