INT 15 - MultiDOS Plus - EXECUTE A MULTIDOS PLUS COMMAND                        
	AH = 0Fh
	DS:BX -> ASCIZA NUL-terminated ASCII string.	The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h.  Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. command
Return: after command has been processed
Notes:	specified string is executed as if it had been typed at the MultiDOS
	  command prompt
	the task is placed on a queue which MultiDOS examines periodically and
	  is suspended until MultiDOS has processed the command
	all lowercase characters up to the first blank are converted to upper
	  case within the given buffer