Add step to rotate screen, fix issue with UIAlertViews in landscape.

The following method should provide hours of fun:

    [system
simulateDeviceRotationToOrientation:UIDeviceOrientationLandscapeLeft];

I used this to validate and fix issues #60 using the approach outlined
in that issue.
Fixed running test on iOS 5 from GM

Storyboard was targetting 6.1 as a minimum version. Lowered to 5.0.
Added test to validate that testFieldShouldReturn: is called when "return" is tapped.

Testing issue #216.
Update README.md

Removed temporary message about Cocoapods.
Removed references to KIF-next.
Updated images to point to kif-framework URL (avoid redirect).