Register List Mask & IO fix

* MOVEM now properly displays the RLM, including pre-decrement mode
* 3 or more sequential registers are displayed as Rn-Rn
* I/O no longer contains bugs when re-starting the program
* I/O checks for inputs greater than 8 characters and displays an error message
* MAX ADDRESS changed to 00FFFFFE
* Instructions for user have been updated for clarification