Revision 202163

* bug 4434: Added support for multiple hosts via spamc -d (comma separated
  list).  This is only documented for spamc and not in the libspamc API, we
  might want to change the implementation at a later point.  Most of the
  stuff stayed logically the same, more or less just added a loop over
  the hostname/hostlist.
* Fixed a possible segfault when transport_setup failed (m->outbuf wasn't
  initialized).
* Added a bunch of asserts to make NULL arguments fail a little bit saner.

TODO:
* Make MAX_CONNECT_RETRIES and CONNECT_RETRY_SLEEP configurable.
* Clean up the message initilization and documentation mess:  Why do we have
  both a m->buf and a m->outbuf when all we do with m->outbuf is allocating
  memory and then assign the pointer to m->out?  Shall m->out be freed or
  does it always point to one of the other members?  How must the members
  be initialized?  Maybe we should add a public message_setup routine which
  assigns the correct initial values?
* Add IPv6 support... doh, Google Summer Of Code submission time is over ;~)