Bug-612: ietf-stateful02 serializers - improved code defense

-check mandatory arguments
-set zeros for missing arguments

Change-Id: I073064da0e3528407b57de5080fbc8a7ed9bd745
Signed-off-by: Milos Fabian <milfabia@cisco.com>
Merge "Bug-612: ietf-stateful02 serializers - improved code defense"