Mercurial repository set up for GCC that mirrors SVN

[Ollie Wild]

> git-svnimport will not pack incrementally as it runs, so it might get
> pretty large.  git-svn offers and incremental repack every x commits
> (I chose 1000) and that did wonders for the import time for me.
> Otherwise it will create a huge number of files before the final pack.

FYI, doing a repack brought the size down from 5.0GB to 266MB.  Aside
from the question of whether or not it's wise to require users to
manually pack their repositories, it looks like the git tree is going
to be about 750MB, which brings it more or less on par with mercurial.

I'm keen to play around with mercurial a bit.  Danny, when is your
repository going to be publicly available?

Ollie