- Redirect only specific domains, ignore rest so that it can be
  chained with proxy for the rest
- document dns_host2ip and dns_domain2srv in Net::SIP::Dispatcher
  and make it truly asnychronous
- do not look up tcp in Dispatcher::resolve_uri  if we have no leg
  which can do tcp
- more tests
- more documentation
  * samples for integration with other loops
- implementation
  * full support for TCP