Do each island completely if avoid_crossing_perimeters is enabled. #278

lib/Slic3r/ExtrusionLoop.pm

@@ -60,6 +60,11 @@ sub split_at_first_point {
     return $self->split_at_index(0);
 }
 
+sub first_point {
+    my $self = shift;
+    return $self->polygon->[0];
+}
+
 package Slic3r::ExtrusionLoop::Packed;
 sub unpack {
     my $self = shift;