clean up some whitespace
register increments itself
define register equality
pull registers into separate class
Delete extracted code from z80
Nop and increment instructions

Feeling around to figure out what should be objects and what is the correct method call sequence.
extract instruction class
simplify interface for manipulating flags
Refactor z80 to use instructions instead of hashes
store instructions in an array by opcode instead of hash by abstract name.

This is a more efficient implementation (one lookup vs two and array lookup instead of hash table).
This is a valid solution since the hash table was using consecutive integers for storage and the values are known a prori.
remove increment instruction from register.

It was redundant and impossible to handle flag setting without increasing the class's sphere of influence
use same instance of cpu for instruction testing.

Avoids setup cost of creating all instructions for each test.
set flags for increment instruction
concatenate registers for 16 bit arithmetic
set up concatenated register access
Rearrange error classes
Sort instructions by opcode.

Easier to find instructions and see what has been implemented
complete increment instructions on registers