* move constant definitions
* always give the client at least quitTimeout to respond to ping,
  even if registerTimeout or quitTimeout are longer than idleTimeout

It's not really used and I'd rather not have it here unless I'm able to actively maintain it properly and build out the web interface.

I might re-add it later but for now I'd rather not have it unless anyone's actively using it.

also, remove the self-notification check; clients are probably not
monitoring themselves, and it doesn't much matter if they are

* Lower ident timeout to 1.5 seconds, as discussed in #oragono
* Enforce connection limits at the granularity of ipv4 /32's and ipv6 /64's
* Raise the limit on number of new connections to 64 every 10 minutes
  (for the benefit of people behind large IPv4 NATs)

* Synchronize map accesses
* Be more aggressive about cleaning up expired lines
* CIDR dlines did not work (nil dereference)