CVS log for: response.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

- pth_writev() is used to combine headers with body instead of issuing
  multiple pth_write()'s; this should be faster because it results in
  fewer internal copies of the data
- filename(s) of index files can be set in cow.conf now
- added ability to limit response concurrency

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

Initial revision