Description:
1. Modify addCiscoNexusVSMCmd to enable a VSM
by default, when it is added to a cluster.
2. Put in two new APIs exposed to the user -
a. EnableCiscoNexusVSMCmd
b. DisableCiscoNexusVSMCmd
Disabling a VSM does not delete it. It only
prevents the Management Server from using that
VSM. This is useful if the VSM is in
maintenance mode.