[Bro-Dev] IPv6 literal addr constants

[Vern Paxson]

> Right, the current rule in scan.l for compressed hex notation looks for
> the first nibble to be a digit and not a letter.  That's fixable ...

I don't recall the genesis of this rule (which I probably added a long
time ago), but it could be that starting with a digit is intentional,
because otherwise examples like the one given earlier of aaaa::bbbb are
fully ambiguous.  With the rule, you can write 0aaaa::bbbb and it will
(should!) parse correctly.  Maybe that's too ugly.  I'm not sure there's
a better fix, however.

		Vern