openflow: Explicitly close connections on quit
openflow: Explicitly close connections on quit

When the system is going down, connections are explicitly
closed now.  We'll see what problems this causes. :)

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