Rename -toProperty:onObject: to -setKeyPath:onObject:
Deprecate -rac_deriveProperty:from:
Update UIBarButtonItem+RACCommandSupport
Update UIButton+RACCommandSupport
Merge pull request #617 from ReactiveCocoa/rename-to-property

Rename -toProperty:onObject: to -setKeyPath:onObject:
Remove -rac_liftBlock:withSignals*:
Merge pull request #620 from ReactiveCocoa/remove-lift-block

Remove -rac_liftBlock:withSignals*:
Merge branch '2.0-development' into signal-for-selector-from-protocol
Try to clarify the behavior of rac_delegateProxy
Reduce the argument tuple
Use unsafe_unretained for delegates, to support OS X