Cpu.execute() modified to enqueue SWI invalid opcode
Cpu.translateAddress() modified to ensure memory protection
Cpu.translateAddress() modified to use SWI's for oob and invalid address errors.
TODO - Better processing of SWI's: clean up memory after process terminates, mark partitions free, clean up the ready queue.
better feedback when loading fails (specifically, say why - like no free partitions, etc...)
  still need a scheduler