Comment 10 for bug 679095

Wow, this was much more serious than I would ever have imagined so I've decided to commit proposed patch.

When PTBatcher was started from another user it started with queue run by another user. If file mask was not correctly set, it was even possible to control that queue. If file permissions were correct, PTBatcher report many error messages to user that files with specified index doesn't exist.

If second user removed these data from his queue and added them back with the same settings it was easily possible to break queue which was run by another user as it was easily possible to create the same output files which would first PTBatcher create later. After some more experimenting I could say that it was pretty easy to break stitching for another user running PTBatcher queue. I've also been able to rewrite existing files created by other user.

Using home directory fixes all these problems except from the problem that other user could create files with the same prefix and break queues which has specified the same prefix, but at least it's not so easy to find out which prefix is set for projects not yet running.