add 2 usefull function for learning switch
Merge branch 'error' into LearningSwitch0x04
LearningSwitch04
fix to add the buffer id
add InPort OXM matching
change the priority of the matching
fix linebreak
Merge remote-tracking branch 'upstream/master' into LearningSwitch0x04
Merge branch 'master' into LearningSwitch0x04

solve the conflict of setup.ml
Merge branch 'roleRequest' into LearningSwitch0x04

Conflicts:
	setup.ml
GroupMod missing function :

  add to_string
  use t type
correct wrong type value
add roundtrip test
Merge pull request #152 from fugitifduck/GroupMod

Group mod missing function
Merge pull request #136 from fugitifduck/LearningSwitch0x04

Learning switch0x04 and Error Message