In case the bridge is only supported at one side, it is technically not considered to be a support, therefore the default infill angle is used. With this change, the bridging areas use the custom angle value even if not supported on both sides.
Fix of the negative XY compensation on multi-material (or multi-region) prints, where the negative XY compensation created gaps between parts.
The XS was left only for the unit / integration tests, and it links libslic3r only. No wxWidgets are allowed to be used from Perl starting from now.
