Otherwise, use software pointer functions.
This fixes graphical glitches on cursor change, when the display driver
provides accelerated pointer functions (DrvSetPointerShape/DrvMovePointer),
but refuses to handle a certain cursor.
These graphical glitches may be reproduced:
- by using Voodoo driver SFFT 1.9
- by using framebuf_new.dll instead of framebuf.dll
- by using the panning driver (setting DefaultSettings.XPanning and
DefaultSettings.YPanning in registry)
When changing pointer cursor:
- use PDEV_HARDWARE_POINTER flag if using hardware pointer
- use PDEV_SOFTWARE_POINTER flag if using software pointer
- keep pfnMovePointer as an accelerator to driver function (if available) and never change it
- fix bug (2 pointers) when switching between hardware and software pointer
When moving pointer:
- check PDEV_HARDWARE_POINTER flag to know if we need to call the driver
- check PDEV_SOFTWARE_POINTER flag to know if we need to call EngMovePointer
