Some suggestions for features:
  trap action=command in xml.c; remove arbitrary detection of unparsed data
  write SOAP methods for http.c to use
  clean up reconnect to lost asterisk server (socket reuse)
  clean up debugmsg instances to add if (debug)
  deal with http non-conformity better, and act on POST MIME-type inputs
  State maintenance modules

Some infrastructure ideas:
  Check for module versions; do not run without modules installed
  tcpwrappers/access control/connect mask?
  libtool/autoconf/automake support
  SetInputFormat proxyaction?