Search the local db to find the local DN using the original DN as search key.
This way we do not have to rely on weak and faulty heuristicts based on DN
names.
Add a few helper functions in the process and change the way we pass members to
sysdb_store_group_send(), instead of passing users and groups list, just add
member DNs to the other sysdb attrs.

If you want to turn verbosity back on, just set the environment
variable CK_VERBOSITY=verbose

- save current ccache file to sysdb
- use the saved ccache file if the user has running processes
- create an empty ccache if offline
- return enviroment variables if offline

Refactor user/group delete functions so that they can be used without a
transaction (they autostart an operation).
Add user and group search function where a subfilter can be specified.

These functions should be used by providers to centrally manage lists of
servers. Servers are grouped into services and each service has it's own
list of servers. If, however, you will try to add a same server into two
different services, they will share a common structure. This means that
a host will only be resolved once.