Renamed notification keys.
Added notification key declarations.
File added.
File added, file removed.
Added sources to test target.
Wrote retain count test.
Paranoia.
Two basic tests written: make sure we can't initialize with a null device ref and make sure we retain for the duration of the lifecycle.
Paranoia.
File added.
Rewrote +devices due to the suspicion that I'm leaking.
Removed duplicate lines.
Flipped order of those two calls, although it's unnecessary to unschedule form the run loop as IOHIDManagerClose() does that for us.