INT 7F - Alloy MW386 - ASSIGN USER TO GROUP                                     
	AH = F8h
	AL = group number
	DL = user number
	DH = machine number (currently 00h)
Return: CF clear if successful
	CF set on error (user already in maximum number of groups)
Note:	each user is allowed eight group assignments
SeeAlso: AH=F9h,AH=FAh