CVS log for: http_message.h

Lots of changes:
 * Use either buffering code taken from Apache or TCP_CORK to minimize
   network traffic.
 * Sockets are now properly 'half-closed' before being truly closed
 * Make 503 responses a compile time option
 * Make HTTP PUT a compile time option
 * Added -b command line switch to change server's accept backlog
 * Lots of code cleanup
 * More statistics kept for verbose (-v) output

- fixed critical bug that caused only the first part (probably about 256K)
  of a file to actually be returned to the user
- CoW was using a pool of pmsg structures for communication between the
  main thread and the depot, but was malloc'ing messages sent from the
  depot to the handlers; messages are now forwarded to handlers instead of
  copied so we avoid the malloc overhead
- CoW now re-uses server socket so we don't have to wait a couple minutes
  after shutdown before restarting (avoids "Address in use" messages)

- added config option to disable TCP Nagle algorithm
- made request.c more lenient in terms of input; also heavily
  cleaned up/commented code

Many changes:
 - beginning of logging support
 - fix bug in Makefile for config.l.c
 - code reformatting
 - prepare for release (AUTHORS, Changelog, etc.)

Initial import of Takashi's CoW code (version 0.3.2).

Initial revision