INT 15 - DESQview v2.50+ - "GETDVXVERSION" - GET DESQview/X VERSION
	AX = DE30h
Return: BX = version (BH=major, BL=minor) or 0000h if not DESQview/X
Notes:	DESQview 2.50-2.53 are distributed as part of DESQview/X v1.00-1.10.
	you must first check the DESQview version to verify that it is 2.50 or
	  greater
SeeAlso: INT 21/AH=2Bh/CX=4445h