Use new GAP logo in icon

[fingolfin]

This is untested. It would be good if someone could verify the resulting GAP executable on Windows has a reasonable icon.

I am in particular concerned about the transparency in the logo and how it looks as a result in practice and how it works as a click target.

It may be better to e.g. add a white disc as background for the logo -- someone would have to try...

[ChrisJefferson]

You are right about the background -- people who set their computer to 'dark mode' can't see the icon, as it's just black with transparency. I wonder if it would look better with a white outline around each piece? That of course wouldn't be visible to anyone whose computer was just set to white anyway.

[fingolfin]

I had a version doing that (white outline) at some point, could certainly make one again. But back then I didn't like it that much in tests, and felt that putting it on e.g. a disc which then itself has an outline, looked better... Or even a background with a gradient, like SageMath uses here ? A long time ago, for my macOS binary bundle I whipped up this icon:

Which of course is generic but it shows what I meant with "gradient disc background with an outline".

(For macOS these days of course one is force to use a "squircle" sigh but we are talking about Windows)

Maybe we just need to whip up some example renderings... perhaps we can even nerd-snipe someone (e.g. @reiniscirpons) into doing that 😁

[fingolfin]

An attempt

[fingolfin]

Updated using icon from gap-system/gap-logo#9 -- @ChrisJefferson could you give it another try?