INT E0 - DR Multiuser DOS - "A_DETACH" - DETACH FROM AUX DEVICE
	CL = A6h
Return: AX = status
	    0000h successfully detached
	    FFFFh detach failed
	CX = error code
Note:	also supported by REAL/32
SeeAlso: INT E0/CL=93h,INT E0/CL=A5h,INT E0/CL=A7h