Major rewrite of markov functionality; see full log

MarkovModel is no longer a template class, and no longer has a compiled in max
order. In fact, it doesn't know anything about order.

Some useful functions we were trying to make in modules/markov are now baked
into the class. This includes picking a random endpoint and providing a smooth
model.

Most places have had queue swapped with list.

Some markov module functions are no longer implemented.
Fix looking up non-existant word in dictionary
No longer take unsigneds by reference
Remove old/broken/moved implementations