Don't try to complete already completed states

Signed-off-by: Casey Dahlin <casey.dahlin@gmail.com>
Tweak aliasable state selection a little more

We now weight states looking to find terminals MUCH more heavily. We also
calculate that weighting correctly. D'oh.

Signed-off-by: Casey Dahlin <casey.dahlin@gmail.com>
Teach tests to differentiate error tokens

Signed-off-by: Casey Dahlin <casey.dahlin@gmail.com>