create action module for incremental action translation

This is mostly moving code out of translate_actions.c and changing the
remaining code to call into the new module.

I removed support for non-standard and otherwise unused actions.
OVSDriver: move indigo_fwd_packet_out to its own file
OVSDriver: remove pktout use of ind_ovs_translate_actions

The OpenFlow actions are directly translated into OVS actions without going
through the intermediate representation.
emit OVS actions directly from the pipeline

Instead of the standard pipeline concatenating the IVS actions together and
then converting them to OVS actions all at once at the end (in the upcall or
kflow code), translate the actions to OVS actions in the pipeline as we get
them.

The translate_actions.c code is moved to a new file in the pipeline_standard
module.
action: assert ctx is not null
OVSDriver: remove packet-in counters

These weren't read anywhere, and are redundant with the per-connection
debug counters.
Merge into master from pull request #182:
Incremental action translation (https://github.com/floodlight/ivs/pull/182)