Ported simplify() to XS and removed dependency on Boost::Geometry::Utils

lib/Slic3r.pm

@@ -33,7 +33,6 @@ our $var = "$FindBin::Bin/var";
 
 use Encode;
 use Encode::Locale;
-use Boost::Geometry::Utils 0.15;
 use Moo 1.003001;
 
 use Slic3r::XS;   # import all symbols (constants etc.) before they get parsed

lib/Slic3r/ExPolygon.pm

@@ -4,7 +4,6 @@ use warnings;
 
 # an ExPolygon is a polygon with holes
 
-use Boost::Geometry::Utils;
 use List::Util qw(first);
 use Math::Geometry::Voronoi;
 use Slic3r::Geometry qw(X Y A B point_in_polygon epsilon scaled_epsilon);