Remove flow-add from OFStateManager flowtable entry

Reviewer: @dtalayco

This reduces the memory consumption of IVS by 18%.

The side effect is that we need to regenerate the wire match from an of_match_t. This means we'll no longer send a byte-for-byte identical match back to the controller. OVS already has this behaviour so I'm willing to claim that as precedent. The only OFTests that relied on this were the flow_query module, fixed in floodlight/oftest#66.