Major rework of Tuple Internals

Switched from a hashcode based model to a fixed constant model. This
means less flexibility, but by defining a strict set of common field
names (UUID, TIMESTAMP etc) and allowing room for expansion and custom
names ghostream will be more efficient and almost as flexible.

This also simplifies the code base (No more HashTable etc.)

List of common fields still needs to be finalised but the current plan
is for 0-128 to be reserved for ghostream and for 129-255 to be
available for custom applications.

ghostream will probably not use all 128 allocated by version 1.