refactor work & fixes:
* moved overlay window logic out of appdelegate into new class GDOverlayWindowController
* moved window controller logic out of appdelegate into new class GDMainWindowControllers
* moved window moving & screen update logic out of appdelegate into new class GDUtils
* moved status item logic out of appdelegate into GDStatusItemController
* refactored window moving logic to incl "gentle" vs. "force" move
* made GDMainWindowControllers, GDOverlayWindowController, GDStatusItemController singletons
* reduced idle memory
* marcosian space (almost) all things!!!