Example of openflowjava extension for nx_action_resubmit

 - configuration file is located in src/main/resources - use this file to load / register this bundle
 - configuration file is exemplary - it registers the NX_ACTION_RESUBMIT into ofjava 6633 and 6653 instances
 - change contains 2 yang files:
   - nx-resubmit-action.yang - shows how to augment existing structures
   - openflow-nx-resubmit-action.yang - shows how to configure custom bundle
 - unit tests test if the structure is (de)serialized correctly

Change-Id: I6ed7226dba83f36deb100de88e5408ae32c060b2
Signed-off-by: Michal Polkorab <michal.polkorab@pantheon.sk>