Use NSObject performSelector: methods instead of NSTimer.
Do a bunch of xcode 5 update shenanigans.
Update for ReactiveCocoa 2.0
Increase the reflow delay from 0.1 to 0.2.

Fixes #47 for now.
Make each space have a unique set of layout objects.

Fixes #48
Fix some unfortunate event handler interleaving that could cause some unnecessary reflows.