Some minor changes

New filetypes to open in scripter plugin. Music player now shows elapsed
time in a cool way.
Hotfix for closing bug

Application.Exit() was evil to use. Close() ensures to check opened
documents within the editor (and no crashes!)
Remove more Thumbs.db files from repo

I think I got them all this time!
Merge https://github.com/Radnen/spherestudio

Conflicts:
	SoundTestPlugin/SoundPicker.cs