This icon was only used for auto-starting a wire, which was
inconsistent with auto-starting a bus or graphic line.
Also the plus sign is a little confusing as it could also be
interpreted as the origin marker (which is really bottom left),
which is also plus-shaped.
Recommendation is to avoid using the year nomenclature as this
information is already encoded in the git repo. Avoids needing to
repeatly update.
Also updates AUTHORS.txt from current repo with contributor names
The native cursor must be set on the GAL canvas wx object,
not its frame (otherwise on GTK the cursor is only set
when we get a request for it from the WM and not immediately).
Fixes https://gitlab.com/kicad/code/kicad/issues/6421
