Tweaks gxt.unload and gxt.load functions.

gxt.unload is now:
- Hiding any easy to find window handles.
- Tweaking the loaded value when unloading a module so the GUI looks correct and reloads work properl.

gxt.load is tweaked so that it calls gizmo.resetEventMap() so that a reloaded module works correctly even though the events and global bindings from the previous load were destroyed and blacklisted by the XPL.