Lock file left when shutting down without database open

[tknarr]

When the program exits without the database ever having been opened, the lockfile isn't deleted. This leads to the program aborting when run until the lockfile is removed manually.

[tknarr]

Issue is intermittent, appears related to terminating the application during log-off rather than just closing the application. Addition of proper X session support should avoid the problem. Code needs changed to allow for removing a stale lockfile on startup. Data loss shouldn't be possible as changes are saved immediately and the save during application termination is a precaution.

[tknarr]

Need to allow forcibly removing the lockfile on startup.