Calendar now segfaults due to faling function
gtk_style_context_remove_provider_for_screen in application finalize method.
As application finalize method is called only when the application closes,
there isn't any hard requirement to cleanup every trailings. Operating
System shall take care of that.
So removing the failing functions so as to not segfault on exit anymore.
https://bugzilla.gnome.org/show_bug.cgi?id=773871
Pressing 'Enter' key shall always save the event.
So focusing on 'Add' button after selecting calendar is redundant.
Instead, focus on the entry, so that the user can add more text without
manually focusing.
https://bugzilla.gnome.org/show_bug.cgi?id=778373
Checking if a new event is already having a source succeeds
for some reason (which should actually fail).
But thankfully we already have an event_is_new gboolean flag.
Check the status of that flag and add or update the event.
https://bugzilla.gnome.org/show_bug.cgi?id=771566