ACC 0 - Minor syntax fixes; output is buggy

In testing this rev testHMM.py gives same tag to all words.

TODO: Add log prob measure and test results
ACC 0- Reorganization of testHMM.py

Created functions to group log conversion and product of a and b values
in testHMM.py. This allows me to change how I do log probabilities in a
more organized manner.

Also changed evalHMM.py such that when unknown count is 0,  however
unlikely, a div by zero error will not occur.