boot: Initialize core later
boot: Initialize core later

We now initialize core during the boot process rather than on import.
This requires a couple other tweaks for things which expect it to exist.

noxrepo/pox,MurphyMc/pox,pthien92/sdn,MurphyMc/pox,pthien92/sdn,MurphyMc/pox,MurphyMc/pox,noxrepo/pox,pthien92/sdn,pthien92/sdn,pthien92/sdn,noxrepo/pox,noxrepo/pox,MurphyMc/pox