Major update to tag parameters

Tag parameters are now a single 32 bit cell instead of a 5 byte packed
string which was easier to use but more awkward internally.

A better solution for tag naming will come soon but for now a rather
basic macro has been added used like this:

_T<A,B,C,D> it only supports 4 characters and no less at the moment.
This will return a 32 bit cell with each letter byte bitwise'd together.