Back out some of the less well thought out ideas from last weeks work on

Back out some of the less well thought out ideas from last weeks work on
winbind default domains, particulary now I understand whats going on a lot
better.  This ensures that the RPC client code does as little 'magic' as
possible - this is up to the application/user.  (Where - for to name->sid code
- it was all along).  This leaves the change that allows the sid->name code to
return domains and usernames in seperate paramaters.

Andrew Bartlett
(This used to be commit 5dfba2cf536f761b0aee314ed9e30dc53900b691)