ADDED DRC test for solder mask aperture bridging copper from different nets. ADDED visualization of minimum web width processing for solder masks. ADDED allow_soldermask_bridges property for footprints. Fixes https://gitlab.com/kicad/code/kicad/issues/2183 Fixes https://gitlab.com/kicad/code/kicad/issues/1792
One test has pads of a bunch of different shapes and provokes some errors to make sure they're caught. The others are all past issues with the zone filler to make sure we don't suffer any regressions. (They should all just pass with no DRC errors.)