Updates the .icns, .ico and .png files used by various distros to show KiCad and KiCad files.
Fixes: lp:1750284 * https://bugs.launchpad.net/kicad/+bug/1750284
Add Dick's workaround in plot_board_layers.cpp to try to avoid crash in solder mask calculations, due to a bug in boost::polygon, in resize function.