Still non-working prediction only

Significant updates and reworking to the CCSDS_codec.py file.
Only prediction section completed, still not working.
Working predictor!

The predictor section of code is now WORKING
It is not optimal, and requires some reworking to play better with other
modules. This code also includes an early stage encoding section (which
is what doesn't play nice with the predictor yet).
Working predictor, testing encoder