INT 15 - DESQview v2.00+ - ENABLE DESQview EXTENSIONS
AX = DE0Fh
Return: AX and BX destroyed (seems to be bug, weren't saved&restored)
Notes:  sends a manager stream with opcodes AEh, BDh, and BFh to task's window
enables an additional mouse mode


15DE0F - DESQview v2.00+ - ENABLE DESQview EXTENSIONS