Add plugs which use the personal-files interface for snaps to allow
the users to enable OpenRocket to access the ~/.java and ~/.openrocket
directories. Currently, these must be manually connected by the user,
so the launcher is updated to ensure the user experience degrades
appropriately when they are not connected.
This method allows for new installations to OpenRocket without any
changes and for users migrating to the snap from the jar to be able
to connect their existing preferences and databases.
Signed-off-by: Billy Olsen <billy.olsen@gmail.com>
ed2f2cbf0a