AD-SAL switch manager does not work

Hi controller devs,

Our CI System Test has detected a regression in AD-SAL NSF functionality:

• For mininet OF10 devices, switch manager shows no node information
• For mininet OF13 devices, switch manager misses some nodes (randomly)

Steps to reproduce:

1) Start controller, install features: odl-openflowplugin-flow-services-ui, odl-openflowplugin-adsal-compatibility, odl-nsf-all

2) start mininet: sudo mn --topo tree,2 --controller 'remote,ip=127.0.0.1'

3) Check switch manager at: http://localhost:8282/controller/nb/v2/switchmanager/default/nodes

By tracing back the error, 2 possible patches show up:

https://git.opendaylight.org/gerrit/16140 (controller message bus)
https://git.opendaylight.org/gerrit/#/c/16821 (yangtool enum)