git-svn: memoize cmt_metadata

Hi,

I have about 150 "branches = ..." and "tags = ..." lines in my .git/config file, and I see a 30x improvement in 'git svn rebase -l' when I memoize the cmt_metadata function. (The run time goes down from ~150 seconds to ~5 seconds on my machine).

I see that it was memoized in version:
* c1927a8 2006-06-27 | git-svn: several graft-branches improvements

and then removed in version:
* 396988e 2007-01-13 | git-svn: get rid of Memoize for now...

Is it safe to re-memoize this function?

Thanks,
Lalit Chhabra