Add handling of [homes] and [printers] via registry shares.

Add handling of [homes] and [printers] via registry shares.

Now homes and printers shares can be accessed through the
registry meachanism on demand in pure registry configurations
with "config backend = registry" without the need to
have a special handler for these two.

Michael
(This used to be commit eec3248ef90fbfe6e048394c875173b164a8b439)