INT 2F C - DESQview v2.50+ External Dev Interface - FREE TASK                   
	AX = DE10h
	BX = mapping context of process (see #00416 at INT 15/AX=1016h)
	DX = task handle of process
Note:	DESQview 2.50+ calls this function before it frees the task; it is
	  similar to AX=DE07h but allows the XDIsee External Device Interface handler to make calls which
	  cause context switches
SeeAlso: AX=DE06h,AX=DE07h