Implemented dispatching response filter
Added path property to simplified response

We use this for filtering on certain response in the response filters.
Updated response simplifier
Implemented conditional path regexp response filter
Implemented JSON decoding
Implemented multipart/mixed normalizing filter
Ensure json_decode returns an array
Implemented remove keys filter
Implemented JSON filter
Refactored response simplifier into message handler
Removed unused method
Tested failures
Tested and fixed mitm dump reader
Added README with basic usage example