BUG-2510: handle RPC route removal

DOM to Binding forwarding ignored removals of RPC implementations. Add
that case back.

Change-Id: I7af1d8b43b9b229cc9a696cfdfc61146f960b374
Signed-off-by: Robert Varga <rovarga@cisco.com>
Shorten YangInstanceIdentifier references

We no longer have InstanceIdentifier name clash, so we can safely import
YangInstanceIdentifier and use it that way.

Change-Id: I48d13f9e6ecd17c1de40b5a017962cfc792810ad
Signed-off-by: Robert Varga <rovarga@cisco.com>
Merge topic 'stable/helium'

* changes:
  Shorten YangInstanceIdentifier references
  BUG-2510: handle RPC route removal