Git mirror changes

[Jason Merrill]

I'd like to make some changes to the GCC git-svn mirror.  Specifically, 
I want to move all the SVN branches from remotes/ into heads/ and split 
the subdirectory branches (redhat, google, etc) into the individual 
branches.

Should I leave the SVN branches as they are in remotes/ as well, for 
backward compatibility with existing users?

Do we want to limit creation of non-personal branches via git?

Any other thoughts?

Jason