Bug 1236 - Documented Binding-aware RPC services of MD-SAL

Documented Binding-aware RPC API contracts

Added simple example / tutorial for routed RPCs.

Change-Id: I0f3a08a392e148732dc218a8ac67bc6f90ea7b0e
Signed-off-by: Tony Tkacik <ttkacik@cisco.com>
Merge "Bug 1236 - Documented Binding-aware RPC services of MD-SAL"