Finished implementing idle message stacking
Minor bugfixes
Added memory bounds checking to CPU's getOperand
Implemented opcode: AD; auto hex->dec in MMU
Implemented opcode: 8D
Fixed inconsistent hex number case when printing
Implemented opcode: 6D
Implemented opcode: A2
Implemented opcode: AE
Implemented opcode: A0
Implemented opcode: AC
Implemented opcode: EA
Implemented opcode: EC

Also fixed some inconsistencies
Implemented opcode: D0
Implemented opcode: EE
Added a comment explaining Cpu.getOperand()
Implemented opcode: FF
Bugfixes