accept paramType=form on properties

fehguy commented on https://github.com/wordnik/swagger-core/issues/107#issuecomment-12976087 that now (as in 3 months ago) `paramType=form` is supported, to execute normal POST-Request (up until then the only way was one big field containing the complete json/xml-structure the server should have expected)

w/o this PR the generated resource files do contain the defined paramType, but you'll get this warning:
    `[WARN] Unexpected paramType "form", expecting "path", "query", "body" or "header" in Controller->method(...) in ./Controller.php on line 1`