Reworked the FFF testing framework & ConfigBase::set_deserialize()
for more compact tests: set_deserialize() now accepts list
of key / value pairs.
Fixed an incorrect assert in LayerRegion.
Layer newly remembers bounding boxes of slices,
the bounding boxes are used by G-code generator & newly the support
generator.
Slices are stored as ExPolygons, not ExPolygonCollection.
Fix of "Bridging infill not connecting with infill set to 0%" #1301
Top, bottom and bridging areas are extended into infill as long
as the infill is not zero. If the infill is zero,
top, bottom and bridging areas wound not expand into these "void" areas.
With this commit, the top, bottom and bridging areas are allowed to expand
into the "void" areas as long as these "void" areas are supported below
with perimeters or some other non-empty infill, and slightly beyond
these supporting areas into the voids (currently hard coded to 1mm).
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.
