Remove unused MD-SAL utilities and interfaces.

This utilities & interfaces were deprecated before
Lithium or were describing internal contracts
of MD-SAL prior to Lithium, thus they are unneeded
in Beryllium.

None of removed classes is used in public Lithium
Opendaylight codebase.

Change-Id: Ie5f51cf3dc15f0f70efe3e51e0fe0d0c2b8da713
Signed-off-by: Tony Tkacik <ttkacik@cisco.com>