Add support for new encoding/decoding for matches

The new specification is based not on the experimenter header wrapping
OXM TLV fields but on the vendor classes in the OXM TLVs.
Do not require och_sigtype as prerequisite for och_sigid.
Update reference to of_protocol/master in rebar.config
Merge pull request #5 from shivarammysore/oe_new_match_spec

Use infoblox vendor class in matches for OE; get rid of prerequisites in OE matches/actions