add sctp_src/dst actions
fix mpls_tc typo
Add explicit cast
Add bucket.weight support
add ipv6/mpls ttl copy

ttl copy requires guessing the inner payload type.
fix action set set-field merging

As described in openflow 1.3.3 spec,
set-field actions are identified by their field types.
Merge pull request #101 from iHiroakiKawai/sctp_action

add sctp_src/dst actions
Merge pull request #102 from iHiroakiKawai/mpls_tc

fix mpls_tc typo
Merge pull request #103 from iHiroakiKawai/bucket_weight

Add bucket.weight support
Merge pull request #104 from iHiroakiKawai/mpls_v6

add ipv6/mpls ttl copy
Merge pull request #105 from iHiroakiKawai/action_set_set_field

fix action set set-field merging