[MERGE] Optimize find_branches for standalone repositories

[John Arbash Meinel]

Aaron Bentley wrote:
> Hi all,
> 
> This patch optimizes find_branches by handing standalone repositories
> specially, since they can't contain nested branches.
> 
> Aaron

Except you can quite easily have a grouping of standalone branches. And
"bzr branches" finds them.

I suppose it depends if your api is meant to be:

give me all branches sharing this repository

rather than

give me all branches underneath this url

You seem to be advocating the former, but we really should be supporting
the latter as well. (I honestly can't say that I want people nesting
standalone branches, but it should be something we support.)

John
=:->