I think we can consolidate git_branch_name and branchname.  In the beginning we had branchname.  Then, when we moved from dist-cvs to dist-git we added git_branch_name because jkeating gave the git branches a different naming scheme than they had in cvs.  Now that we've had nothing but git for years we can probably get rid of one of them.

Even if we want to keep both for what we return when asked for information about a collection, we should probably remove one of them from create_collection() and just set the git_branch_name to be what was given to us for branchname.