Faster support generation. Includes a new implementation of the Douglas-Peucker algorithm

lib/Slic3r/ExtrusionPath.pm

@@ -45,6 +45,13 @@ sub clip_end {
     }
 }
 
+sub clip_with_polygon {
+    my $self = shift;
+    my ($polygon) = @_;
+    
+    return $self->clip_with_expolygon(Slic3r::ExPolygon->new($polygon));
+}
+
 sub clip_with_expolygon {
     my $self = shift;
     my ($expolygon) = @_;