Adds UIGestureRecognizer support improvements to CHANGES.markdown
Adds a stub for UINavigationController

in iOS 8+ the navigation stack is managed asynchronously internally, so we have to forward the run loop one tick in some cases.
UINavigationController+Spec supports -topViewController and -visibleViewController
Adds support for naive delegate messaging when pushing/popping

Other UINavigationControllerDelegate methods not supported yet
Remove tests of UINavigationControllerDelegate and introduce an assertion handler.
Refactors UINavigationController+Spec to pass through to the internal push/pop methods without animation

No more advancing the run loop
iOS 8.1 wants UINavigationController tests to happen inside a window, otherwise "unbalanced calls to begin/end transitions" will emit
iOS 8.1 has a bug in 64 bit simulator where some internal assertions don't happen, and therefore some specs will fail on that runtime (http://openradar.appspot.com/18831038)
Fixes a subtle bug which required compilation with ARC disabled
Also cleans up the assertion handler test in UICollectionViewCell+Spec
Updates podspec to remove manual reference counting requirement for UINavigationController+Spec
Merge branch 'master' into UINavigationControllerStub

Conflicts:
	UIKit/UIKit.xcodeproj/project.pbxproj
Refactor to use PCKMethodRedirector
Merge pull request #95 from pivotal/UINavigationControllerStub

Adds a stub for UINavigationController to support iOS 8 changes