Simplify the match condition.
Change Match to take Runes and match next with wrapping.

Runes are necessary because next match needs to run the automata from each subsequent rune until it finds a match (this is what Acme, sam, and friends do). That requires the ability to read a bunch of runes, fail, go back and read more from the beginning again. RuneReader doesn't allow this since it consumes runes; you can't get them back. I was hoping to use some cool finite automata trickery to get past that. I can't. Nothing that I tried worked correctly.

Anyway, this isn't so terrible. It gets rid of the error return from match.
Merge pull request #14 from eaburns/re1

Change Match to take Runes and match next with wrapping.