Software cursor mode is now supported, although currently the existing hardware
cursor mode is used whenever possible. (Software mode will be used if you are
running with a recent version of SDL's Quartz video driver, since a bug in SDL
1.2.11 and later prevents the hardware cursor from working properly with that
driver.)
In hardware cursor mode, the hot-spot is now determined heuristically. Formerly
it could not be determined and was always (1,1), an annoyance for many cursors
other than the arrow.
In hardware cursor mode, the cursor will now be hidden when requested by the
emulated OS (such as when you are typing in a text field).
In hardware cursor mode, some cursor image formats that the code does not handle
correctly will now be rejected, causing the emulated OS to revert temporarily to
software cursor mode. Formerly you would just end up with random garbage for a
cursor. This typically happened for grayscale or color cursors; rejecting images
with rowBytes != 2 eliminates the worst cases.
recompile with "mac_cursor_enabled" constant set to true. Disabling it
causes a better looking cursor that is not "disappearing" sometimes with
e.g. Microsoft Internet Explorer.
mode as the stack is corrupted and we are jumping to garbage when moving
the mouse. Also add 1152x768 resolution from PBG4, but make timing match
the 1152x870 version.
Cleanups, further merges from Basilisk II tree.
