Comment 8 for bug 597838

I have examined the diff::

 $ svn diff -c 5861 svn+ssh://<email address hidden>/home/osi/bfgsvn/karl/branches/community_tags_optimization

The main change looks good -- do we have enough test coverage for the cases
with / without communities to be confident that adding / using the index doesn't break
anything?

There seem to be some stray changes in the diff (comments in an older evolve script,
an apparently unrelated test), but they look harmless.

+1 for merge.