[Micheus]

Fixing a mouse pointer issue on wings_wm which was forcing it to the default
arrow even we setting it to a different one for the app or a specific window;

I noticed that by implementing a mouse pointer changing for an operation and
the pointer started to blink preserving the arrow look.
The changes to the code preserves de current option to change the cursor point
for all the application (top_frame) and add the option to change it by window,
which is a better approach for multi-window UI. It also exports options to allow
the coder handler better this stuff.

In the sample bellow we see it working only for geometry window and conditionated
to be moving over a valid place:

[Micheus]

@dgud I would appreciate if you could accept this fix (or suggest any change) to make it available for the next release. This way I can keep my project knowing this will not be a problem in the future. Thanks.