Rename REQ_BODY_ modes to WITH[OUT]_LEN rather than transmission mode.
Minor polish
Use WRW's facility for sending chunked req.body to backend
Fix reference

Spotted by:	Dridi Boukelmoune
Split beresp.body status determination into transport protocol
dependent (is there a C-L header ?), and semantic (ie:  HEAD request
doesn't have body, even if the response has C-L etc.)
Start ignoring lower case ctags file.