Major code & warning cleanup.

Removed all warnings except a deprecation one and added two others for things that bothered me :
- converting an image for use in an OpenGL context (which I have no idea how to fix)
- not observing screen resolution changes
- hardcoding the "No Sound" localizable string from Quicksilver
Deliver gestures changed notifications immediately.

Else gestures changes would not be picked up by Abracadabra until another one was triggered.
Launch Abracadabra when the Gesture plugin gets loaded.
Cruft.
Write the gesture file atomically.

Just in case anything goes wrong ;-).
Merge pull request #1 from quicksilver/cleanup

Cleanup