loggerhead as a plugin

[Martin Pool]

I did a little of work picking up from mwh's branch so that loggerhead
will work as a plugin.  It's in
<https://code.edge.launchpad.net/~loggerhead-team/loggerhead/loggerhead-plugin>.
 If you do

  bzr branch https://code.edge.launchpad.net/~loggerhead-team/loggerhead/loggerhead-plugin
\
     ~/.bazaar/plugins/loggerhead

then the 'bzr serve' command will get a new --http option, which will
run up a loggerhead viewer on branches under the current directory.
jml and beuno have a separate patch that lets loggerhead act as a bzr
server, and the combination should be pretty nice.

-- 
Martin <http://launchpad.net/~mbp/>