Started some refactoring work.
Simplified longPress*
Enhanced entering/clearing text.
Slight API improvement for waiting for the element and its view.
Simplified the switching logic to be linear and take advantage of new APIs.
Simplified error helpers.  Removed several usages of runBlock:
Added test for clearing text.  Simplified, enhanced test for waitForTimeInterval.
Standardized the API.  Documented and exposed some new methods.
Made KIFTestActor conform to KIFTestActorDelegate

By making it conform, actors can now invoke other actors inside their
methods using the standard shorthand.  At this point, the errors will
be reported with the appropriate test but appear in their own source
file.