- removed ascii headers from reply and request structures

- removed ascii headers from reply and request structures
- added more http headers
- fixed content of entity-headers array
- do not update headers with 304 that are not allowed by HTTP/1.1
- moved routines common for request and replies to HttpMsg.c
- rewrote clientBuildReply* and other client_side functions
  using new header interface
- code cleanup
- do not cut off "; parameter" from "digitized" Content-Type
  http fields
- Added X-Request-URI for persistent connection debugging