[dev] Auth drivers and configurable capabilities, ldap groups hierarchy

[Chuck Hagenbuch]

Quoting Ben Klang <ben at alkaloid.net>:

> 2) Find a new way to represent hierarchical groups within the Horde
> UI.  This may require breaking BC by changing the way we pass in
> hierarchical group information to the Group API as the old Datatree
> driver expects hierarchical groups to be passed in as colon-delimited
> string.

I think this should be done, and addressed as part of Horde 4.

-chuck