Update Notification, Bug Fixes

This little update adds automatic update notification. I've tried to make it as non-nagging as possible. If you don't like it, you can switch it off under Tools | Options | MDK/SE.

I have also fixed some bugs, like a crash and deployed scripts not getting a thumb (thanks Elfiwolfe). By default the thumb will promote MDK, but you can switch that off too in the options screen mentioned above. Or, if you prefer, you can replace the thumb with your own. Once a project is created the thumb.png file is not touched by the system other than being copied during deployment.

As usual this is a prerelease, meaning I need your help with testing: I'm just one guy, I can't test thoroughly. Please help me reach version v1.0!