* The resulting instance window can be closed at any point.
* Main window is kept open and running instances are marked with a badge.
* Multiple instances can now run from the same MultiMC - it's even more **multi** now.
* MultiMC can be entirely closed, keeping Minecraft(s) running.
Added an 'add mods' button to the version page
Add jar mods now has a very angry nag dialog until it's used successfully
Buttons on version page are rearranged to deemphasize jar mods
