Added support for NOS version 4.1.0, 5.0.0 and greater

NETCONF temaplates for NOS version greater than 4.1.0 are slightly
different (argh). An init time check of the NOS version is done
to enable selection of the correct NETCONF templates.

Change-Id: I01e82ad402fbbb25d92a99a3325ca2608dd514cb
Closes-bug: #1332719
Merge "Added support for NOS version 4.1.0, 5.0.0 and greater"