The non-mac icon was an old version with white foreground and a
completely transparent background, but this looks bad (or invisible)
depending on where you view it. This updates it based on the macos
icon, but with a round white circle background instead of the macos
"squircle" background.
This also replaces the .ico file for the installer with one that we
build during the win32 build rather than a pregenerated one.
Bumps the gui as well to a version with the new icons in place.
The old one was way too big on mac relative to other icons. This scales
the background down, while keeping the black logo parts the same, and
changes the rounding of the corners to match native macos apps.
This also rewrites it from scratch to use a useful coordinate system
which allows drawing all the fundamentals in much more useful units.
