Qt on macOS automatically adds these entries to the menubar of GUI apps,
providing that such apps have an Edit menu at their startup.
Hence, this commit contains the following changes (macOS only):
- create the menubar in the first dialog shown by the app (GuiConfiguration)
- create an Edit menu, populate it with Cut/Copy/Paste/Select all actions
- connect system-wide shortcuts to these new actions
- pass the menubar and the Edit menu to the MainWindow through config and
through an added optional argument in getUI and GraphicalUI
- populate the menubar created before and not a new menubar in MainWindow
- provide localized strings for the entries in the Edit menu
- add xx.lproj folders in Syncplay.app/Contents/Resources/ to allow
automatic localization of the entries added by the OS
Known issues:
- automatically added entries will always be in the OS language
- the Edit menu might retain the previous language after a language
change in the app settings. Reboot the app solves the issue.
- the automatically added entries might disappear if the app language
does not match the OS language
