Add an ability to hook into webapi method view calling.
Review Request #6086 — Created July 9, 2014 and submitted
WebAPIResource.__call__ no longer directly calls the method-based view
(get, create, etc.). Instead, it calls the new call_method_view()
function, which defaults to calling the view. Subclasses can override
this to perform additional checks or pass additional data without having
to decorate all views.
Successfully overrode the function in a subclass and was able to short-circuit
calling the view.
Unit tests pass.