openflow_input: add missing "_t" suffix to list members
openflow_input: fixup standard-1.4

 - Add "== ?" syntax to discriminators.
 - Add inheritance.
 - Use of_octets_t for opaque data.
 - Remove _header suffix from inheritance roots.
 - Change 'ofp_' to 'of_' in struct definitions.
Merge pull request #315 from rlane/of14-input

Fixup OF 1.4 input file