We generally add some jitter to the raytracing lines in order to smooth
out over multiple iterations some of the imperfections. However, when
we do this to an orthographic projection (where all lines are parallel
to start, we don't average and just introduce noticeable noise in the
render
Fixes https://gitlab.com/kicad/code/kicad/issues/8863
Now that we are threading things in different frames, we need to watch
that we are not waiting for a process to complete in one frame while
working in another. To accomplish this, we only wait for our own loop
results
Fixes https://gitlab.com/kicad/code/kicad/-/issues/20572
Having thread pool as its own singleton in the library meant that each
kiface had its own threadpool, leading to many multiples of the threads
being started. Placing a singleton class in PGM_BASE ensures that all
kifaces use the same thread pool.
The singleton class can be extended to provide single instance
guarantee for any element across kifaces
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
