INT 21 - Phar Lap 386/DOS-Extender VMM - UNLOCK PAGES

	AX = 251Bh
	EDX = number of pages to unlock
	if BL = 00h
	    ECX = linear address of first page to unlock
	if BL = 01h
	    ES:ECX -> pointer to first page to unlock
Return: CF clear if successful
	CF set on error
	    EAX = error code
		09h invalid address range
SeeAlso: AX=251Ah,AX=EB07h,INT 31/AX=0601h