Setting the official branch for a charm.

[Clint Byrum]

Wow, we've got quite a few official charms now, and I've noticed that
some of the official branches are not owned by "charmers" (the former
ensemble-composers).

It happens if you just push your branch to lp under a non official path
and the to lp:charm/foo

So, to set the official branch to be by charmers, anybody in the team
can use the "promulgate" tool from charm-tools.

To do this, there's a two step process:

in the bzr branch for the charm, do these too commands:

bzr push --remember lp:~charmers/charm/oneiric/foo/trunk charm promulgate

Note that the charm-tools package is only available in ppa:juju/pkgs, and
has only just now been updated to make 'charm promulgate' work properly.