Merge branch 'release0.3.12' into develop
Add a predicate method for LLDP frame. See #252.
Fixes undefined method `prerelease?' error.
Merge branch 'develop' of https://github.com/trema/trema into develop
Add FeaturesReply#physical_ports iterator.
Version bump to 0.3.13
Merge branch 'release0.3.13'