lib.addresses: Remove EthAddr int stuff
lib.addresses: Remove EthAddr int stuff

This closes issue noxrepo/pox#26

This removes the code to convert EthAddrs to and from int/long
which had been added at some point.  Doing this is problematic
and we don't want to encourage it.

Also, document some parts of the code.

Also incorporates Sam's removal of some duplicate functions
from d4d53f22062dd9ec2725d393702da7f332d7c7e5

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