Apply my experimental aliases support to HEAD. This will be a bit difficult to

Apply my experimental aliases support to HEAD. This will be a bit difficult to
merge to 3_0, as the pdb interfaces has changed a bit between the two.

This has not been tested too severly (which means it's completely broken ;-),
but I want it in for review. Feel free to revert it :-)

TODO:

make 'net groupmap' a bit more friendly for alias members.

Put that stuff into pdb_ldap.

Getting the information over to winbind. One plan without linking pdb into
winbind would be to fill group_mapping.tdb with the membership information and
have that as a cache (or use gencache.tdb?). smbd on a PDC or stand-alone
could trigger that itself, the problem is a BDC using LDAP. This needs to do
it on a regular basis. The BDC smbd needs to be informed about SAM changes
somehow...

Volker