shortcuts: fix Ctrl+N and add Ctrl+Q and Ctrl+W as quit actions
The Ctrl+N keyboard shortcut didn't work.
Support both Ctrl+Q and Ctrl+W to quit the app.
(Tweaked by Philip Withnall to fix redo shortcut.)
The Ctrl+N keyboard shortcut didn't work.
Support both Ctrl+Q and Ctrl+W to quit the app.
(Tweaked by Philip Withnall to fix redo shortcut.)