[MERGE] install plugin l10n files with Windows binaries.

[Mark Hammond]

> Anyway, *this* patch is fine, and can be merged for 1.7, 

It appears this patch didn't make 1.7rc1 - but it would be nice to have it
in the next 1.7 release - the fix is trivial and non-english users of QBzr
will appreciate it.

> For details, see:
>
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C001801c90dc7%24eb
f51410%24c3df3c30%24%40com.au%3E
> Project: Bazaar

Cheers,

Mark