ACC 95 by what

I discarded doing smoothing and discounting for unknowns, as unknown
calcs were somehow wrong, and did a simple 1/sum stupid GT est for
unknown obs and trans.

This resulted in an acc of 95%, up from 0% and from 60% of many revs
ago!

TODO: fix count of unknown events; eval reports no unknowns prob due to
skipping of count increment in testHMM
small change to mark unseen events right