libopenflow: Make wire-wildcard-fixing optional
libopenflow: Make wire-wildcard-fixing optional

This makes the fixup for wildcards for the wire an optional
feature (and also does a bit of formatting/docstring tweaking).

pthien92/sdn,denovogroup/pox,kavitshah8/SDNDeveloper,PrincetonUniversity/pox,kavitshah8/SDNDeveloper,denovogroup/pox,waltznetworks/pox,VamsikrishnaNallabothu/pox,PrincetonUniversity/pox,kulawczukmarcin/mypox,waltznetworks/pox,andiwundsam/_of_normalize,pthien92/sdn,waltznetworks/pox,adusia/pox,andiwundsam/_of_normalize,jacobq/csci5221-viro-project,waltznetworks/pox,jacobq/csci5221-viro-project,adusia/pox,kpengboy/pox-exercise,xAKLx/pox,MurphyMc/pox,carlye566/IoT-POX,PrincetonUniversity/pox,kulawczukmarcin/mypox,kulawczukmarcin/mypox,waltznetworks/pox,PrincetonUniversity/pox,MurphyMc/pox,adusia/pox,noxrepo/pox,adusia/pox,chenyuntc/pox,VamsikrishnaNallabothu/pox,diogommartins/pox,kavitshah8/SDNDeveloper,kpengboy/pox-exercise,jacobq/csci5221-viro-project,pthien92/sdn,kulawczukmarcin/mypox,pthien92/sdn,jacobq/csci5221-viro-project,xAKLx/pox,VamsikrishnaNallabothu/pox,diogommartins/pox,chenyuntc/pox,jacobq/csci5221-viro-project,MurphyMc/pox,chenyuntc/pox,kulawczukmarcin/mypox,noxrepo/pox,carlye566/IoT-POX,carlye566/IoT-POX,noxrepo/pox,xAKLx/pox,carlye566/IoT-POX,MurphyMc/pox,xAKLx/pox,chenyuntc/pox,VamsikrishnaNallabothu/pox,kpengboy/pox-exercise,VamsikrishnaNallabothu/pox,diogommartins/pox,kpengboy/pox-exercise,noxrepo/pox,denovogroup/pox,andiwundsam/_of_normalize,MurphyMc/pox,kavitshah8/SDNDeveloper,denovogroup/pox,chenyuntc/pox,pthien92/sdn,xAKLx/pox,andiwundsam/_of_normalize,carlye566/IoT-POX,diogommartins/pox,PrincetonUniversity/pox,diogommartins/pox,kpengboy/pox-exercise,denovogroup/pox,adusia/pox