OVSDriver: remove flow and table management

This is all moved to the individual pipelines.
OVSDriver: remove packet-in suppression feature

Not used anymore.
OVSDriver: remove bsn_interfaces extension

Not used any more.
remove flow-based GRE tunnel support

Not used any more.
remove max-flows setting

This should be enforced by the pipelines on a per-table basis.
update indigo

* submodules/indigo 1265258...12b2d6b (5):
  > Merge into master from pull request #139: Add operation to get table stats (https://github.com/floodlight/indigo/pull/139)
  > Merge into master from pull request #141: Add a config for default OF version for async message. (https://github.com/floodlight/indigo/pull/141)
  > Merge into master from pull request #143: fix leaking socket desc while try to reconnect to a controller (https://github.com/floodlight/indigo/pull/143)
  > Merge into master from pull request #140: OFStateManager: fix flow checksum use of table_id (https://github.com/floodlight/indigo/pull/140)
  > Merge into master from pull request #137: OFConnectionManager: drop more types of messages when the write buffer partially fills (https://github.com/floodlight/indigo/pull/137)