Added ability to remove id mappings in wbinfo and libwbclient.
The idmap_tdb backend already provides an interface to remove existing id
mappings. This commit plumbs that ability up through, winbindd, libwbclient,
and wbinfo.
Added new winbindd command:
WINBINDD_REMOVE_MAPPING
Added new libwbclient interfaces:
wbcRemoveUidMapping() and wbcRemoveGidMapping()
Added new wbinfo options:
--remove-uid-mapping
--remove-gid-mapping
Increased libwbclient version to 0.2
Increased winbind interface version to 20