Cleaned the WGI_CHUNKED_INPUT_STREAM and provides access to last extension, last trailer, ...
Improved WSF_TRACE_RESPONSE to support tracing chunked input back to the client.
Merged REQUEST.input and REQUEST.chunked_input
Now REQUEST.input handles directly the chunked transfer encoding, or the non chunked.
Kept REQUEST.is_chunked_input since it matters that Content-Length is 0 even if there are input (chunked) data.