Light pen now working in the gui app

[Bill E]

The line drawing demo and the tracking demo are also now in .../FunStuff/Demos.

The program selector is also there, and actually useful.

You might have to play with the 'display' size a bit to get good hit response. Too small is not good. I think I'll add a setting in the config file to provide a hint to the light pen support what the physical size of the display is.

Currently, the code assumes the original 1024x1024 pixels. P7sim and the gui app do some internal rescaling to normalize the displayed window coordinates to 1024 but with too small a display the hit location precision goes way down.

The defines for the aperture sizes as the original pen had are the aperture diameter in

pixels as a fraction of 1024. And yes, the 'aperture' is circular, just like the original.

Finally, I've spent a lot of time tweaking the tcp settings used by the socket the lp data is read from, on both sides. Pen tracking is now much improved, especially in p7sim.

Still looking for a volunteer to do the web client changes!

Bill