OFStateManager: pass cxn_id to gentable operations

The cxn_id is needed for barrier blocking.

Backwards compatibility is maintained since this adds new function pointers
that are used in preference to the old ones. The old function pointers are now
deprecated and will be removed when all callers are switched over.
Merge into master from pull request #178:
OFStateManager: pass cxn_id to gentable operations (https://github.com/floodlight/indigo/pull/178)