* refactor responder and dummy_responder argument checking to take
  sanity-check presence and absence of all expected arguments, and
  check most arguments for approximately-correct type
* ApiSpec.php is a new dependency of DummyResponder.php, so we need it for jenkins testing too
* checkstyle warnings, including a debugging statement i left in
Merge pull request #682 from cgolubi1/674_post_sanitize

refactor ApiResponder and DummyApiResponder to sanity-check all function args