changed the way request Accept header is handled, no longer using default response type from config

addresses #13
closes #10
removed (now obsolete) config/restful.php and respectively updated README

closes #13
POST will only be un-cacheable now if no Cache-Control or Expires headers not set

closes #14
Merge branch '3.3/feature/14-post-uncacheable' into 3.3/develop
removed RESTful_Response::get_renderer() and replaced it with getter/setter RESTful_Response:::renderer()
left deprecated RESTful_Response:::register_renderer() for legacy reasons

addresses #15
removed RESTful_Request::get_parser() and replaced it with getter/setter RESTful_Request:::parser()
left deprecated RESTful_Request:::parser() for legacy reasons

closes #15
Merge branch '3.3/feature/15-properties-retreival' into 3.3/develop
removed unnecessary interfaces and updated parser and renderer classes

closes #16
consolidated request parsers into one class
consolidated response renderers into one class
also json is now not formatted anymore
Merge branch '3.3/feature/16-interfaces' into 3.3/develop
whitespace and coding style tweaks