Fix endianness detection on OS X

Signed-off-by: Sergey Nizovtsev <snizovtsev@gmail.com>
Fix default constructors of OXMTLV subclasses

Signed-off-by: Sergey Nizovtsev <snizovtsev@gmail.com>
Make OXMTLV getters constant
Optimize PacketIn getters
Remove one std::vector from of13::Match
Merge pull request #4 from ARCCN/master

Endianess and OXMTLV fixes
Merge pull request #6 from bertvl-netro/icmpv4_type_fix

Bugfix: ICMPv4 TYPE match using incorrect enum.
Merge pull request #7 from bertvl-netro/match_mask_fix

Bugfix: Incorrect length when using masked matches.
Merge pull request #8 from bertvl-netro/clear_actions_fix

Bugfix: Clear-Actions instruction too long.
Merge pull request #9 from bertvl-netro/duplicate_match_fix

Bugfix: segfault with duplicate match fields.
Merge branch 'master' into dev