Minor optimization

- Increase number of slots to 250
- Add categories: General (old default category), Events, GFX, Utilities, Other (each has 250 slots)
- Add category launcher (the launcher is smart enough to determine if you've got mods in more than 1 category and will determine whether to launch mod category launcher or the mod category -- if you've got mods in only 1 category)
- Handle slot deactivation\uninstallation

Added alt-m hotkey to launch dmm menu

Minor gui change (longer header line)

Re-add the gui button (tired)

Small fix

Initial version