illumos gate

The current nfs/server service server_versmax and server_versmin property types are number - which is integer data type and does not allow us to specify minor numbers. provide mechanism to upgrade the internal data type to string, so we can add support for minor numbers later.

Testing done: used sharectl get and sharectl set commands for nfs protocol to observe and change version values. Verified with rpcinfo which server versions are registered with rpcbind and confirmed mount command success/failure depending on server min/max version number values.