Started chipping away at KIFTestStep.

KIFTestStep.h no longer referenced by other headers.
KIFTester+Generic no longer uses KIFTestStep.
Notification test allows execution of arbitrary block while executing.
Refactored large chunks of KIFTestCase.

Removed dead notification code.
Moved scrolling and waiting for first responder to KIFTester.
Moved accessibility element code to appropriate place.
Absorbed stepToWaitForViewWithAccessibilityLabel:*
Extracted private methods from KIFTestStep.
Moved setOn, tapRow, firstResponder
More cleanup.