ioworker: Allow positional args; catch recoco exit
ioworker: Allow positional args; catch recoco exit

new_worker() used to only take keyword arguments.
Should probably have a new_custom_worker() or something for
specifing the class.

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