[MERGE] optionally install tbzr binaries with bazaar binaries on Windows

[Ian Clatworthy]

Mark Hammond wrote:
> Attached is an updated bundle which should address most of John's comments,
> apart from the environment variables and the general concerns about bundling
> tbzr at all.

This looks good enough to merge after a tweak or two.

bb:tweak

> +    # And it uses funky mappings to conver to 'Oldname' to 'newname'.  As

conver to -> convert from

Can you make the tweak above, consider those John requested and re-post the
patch please? I'll then merge it.

Ian C.