[MERGE] Replace Repository.__eq__/__ne__ methods with Repository.is_same_repository

[Andrew Bennetts]

Robert Collins wrote:
[...]
> > 
> > I don't follow you — the tests for this method already are in
> > repository_implementations, and so get run for all repository formats.
> 
> its in test_repository.py, which is an overly large python file. I
> suggest test_has_same_location.py 

Ah ok.  Done.

-Andrew.