[MERGE] Enable setting and getting make_working_trees for all repositories

[Andrew Bennetts]

Aaron Bentley wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hi all,
> 
> This patch enables set_make_working_trees on all repository
> implementations.  For repository implementations where it cannot be
> changed, it raise ValueError if called with "False".

I don't like using ValueError for this.  For that matter, I don't really
understand how this is a significant improvement over raising
NotImplementedError.

[...]
> === modified file 'bzrlib/remote.py'
[...]
>      def make_working_trees(self):
> -        """RemoteRepositories never create working trees by default."""
> -        return False
> +        """See Repository.make_working_trees"""
> +        self._ensure_real()
> +        return self._real_repository.make_working_trees()
>  
>      def revision_ids_to_search_result(self, result_set):
>          """Convert a set of revision ids to a graph SearchResult."""
> @@ -994,7 +995,8 @@
>          return self._real_repository.pack()
>  
>      def set_make_working_trees(self, new_value):
> -        raise NotImplementedError(self.set_make_working_trees)
> +        self._ensure_real()
> +        self._real_repository.set_make_working_trees(new_value)

I'm fine with this part, though.

-Andrew.