Proper hand names.
Allow a hand comparator to be passed to the searchers.
Did some score analysis, adjusted hand scores.

Basically I had the AI play a bunch of games against one another, ranking hands
by length (more cards is better). I used the hand frequencies there to come up
with a first pass at scoring, then I reran the AI using those score values to
see if it was stable (i.e. pretty close to the "rank by hand length" values).
From there I tweaked things a smidgen more.