…on original Net::HTTP, after WebMock is disabled, if any constants were added to Net::HTTP after WebMock was enabled.
…ns a 3xx response and the :redirects option is set, the globally_stub_request/after_request hooks are now fired for the original request and the redirect-following request.
When the a request was not stubbed, the `nil` value of the webmock response was being cached in the `webmock_responses` hash. Then, when a second request was made with the same HTTPClient instance and an identical signature, it was not checking for a stub again, even though there may have been one for the second request (e.g. when using a global stub hook or if another stub is registered between the 1st and 2nd requests). Fixes myronmarston/vcr#190.