Optimization: use Boost.Geometry for point in polygon
Removed useless code
Removed wrong optimization causing possible extra retractions while moving in infill space
New algorithm for overhang detection
Note to self in code
Some fixes about overhang detection. Includes regression tests
Add regression test to ensure fan is enabled when printing overhangs. #432
Limit fan speed to 100% :-)
Merge branch 'master' into new-support2