Now uses versioned Counter class in core.counting everywhere. Old unversioned coring.Counter has been removed.

[SmithSamuelM]

This is the first major step in supporting verisoned CESR with versioned count codes.
Next steps,

• Change parser and other places that parse count codes to dynamically determine version of incoming message stream and apply the correct version of Counter with count codes.
• Make default generation of count codes in output streams use the version 2 codes which requires that generation logic convert to always counting quadlets not groups of primitives.

[SmithSamuelM]

@pfeairheller I didn't merge this yet because wanted you to be appriased of it. I checked and it does not break anything in Keria, because Keria does not directly reference Counter or CtrDex. I didn't know if something else might break.

[SmithSamuelM]

The last commit breaks Keria so I fixed Keria as well but keripy needs new dev tag to github tests pass for keria