* Add a test suite for the mercurial backend, contributed by Emanuele Aina.

* Add a test suite for the mercurial backend, contributed by Emanuele Aina.
* Add a test suite for the svn backend.
* Daemonize before sending RPC pings, since that can take a while
  and/or hang.
* Daemonize before sending commit mails, as that can also take a long
  time/hang if the mail server is unhappy.
* Factor out commit mail sending code into new function.