INT 31 P - CauseWay - "LockMemNear" - LOCK APPLICATION-RELATIVE MEMORY REGION
	AX = FF1Fh
	ESI = starting application-relative linear address
	EBX = size of region in bytes
Return: CF clear if successful
	CF set on error
Desc:	prevent memory from being swapped out by the virtual memory manager
Note:	locks are applied on 4K page boundaries, so memory above and below
	  the specified region may be locked as well
SeeAlso: AX=FF1Ch,AX=FF20h