New Program Flow

Instruction checks are now sub-routines so that the OP master can
continue to check other instructions.
New sub-routines have been provided for instructions to make life
easier.
Some new variables are introduced to avoid mixing inputs and outputs in
the data registers.
OPSIZE now supports all OP modes.
TESTAM has been added to test the valid addressing modes.
Comments have been added to all instructions for reference.
Many other changes and additions.
Updated Nguyen's test file.