a few minor updates to hacking

        Also implements parsing functions to read HTTP and SOCKS commands

        from buffers.

     tree.h -- A splay tree implementation by Niels Provos.  Used only by

        dns.c.

     tree.h -- A splay tree implementation by Niels Provos.  Used by

        dns.c for dns caching at exits, and by connection_edge.c for dns

        caching at clients.

     config.c -- Code to parse and validate the configuration file.

   [Background processing modules]

     cpuworker.c -- Implements a separate 'CPU worker' process to perform

     cpuworker.c -- Implements a farm of 'CPU worker' processes to perform

        CPU-intensive tasks in the background, so as not interrupt the

        onion router.  (OR only)