Added thread-safe tasks that will be run by the trema thread.
Added missing header files for Tasks feature.
Added options to disable various signal handlers in init_trema.
Merge branch 'edge' into feature-disable-sighandlers
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
fix memory leak
fix oxm.length changes
fix memcpy overlap

There was src=dst use case.
Merge pull request #106 from iHiroakiKawai/fixes

various tiny fixes
fix compiler errors -O3

* "dereferencing type-punned pointer will break
strict-aliasing rules"
* missing initializer
* boundary