[nox-dev] Possible bug in nox-classic nox.cc

[Mabry Tyson]

I happened to notice this potential bug.  I don't know whether there is 
something else that might avoid this.  And, again, I saw this in Nox 
Classic.  Maybe Nox/Pox does things differently, or maybe they have the 
same issue:

nox.cc tells the switch to delete all the rules on registration of a 
switch.  Shouldn't a barrier message be sent immediately after that?  It 
would seem that otherwise a rule added after this might wind up getting 
deleted.