Remove all id() and ordered_id() methods

lib/Slic3r/ExtrusionLoop.pm

@@ -1,6 +1,8 @@
 package Slic3r::ExtrusionLoop;
 use Moo;
 
+use Slic3r::Geometry qw(same_point);
+
 # the underlying Slic3r::Polygon objects holds the geometry
 has 'polygon' => (
     is          => 'rw',
@@ -57,7 +59,7 @@ sub split_at {
     # find index of point
     my $i = -1;
     for (my $n = 0; $n <= $#{$self->polygon}; $n++) {
-        if ($point->id eq $self->polygon->[$n]->id) {
+        if (same_point($point, $self->polygon->[$n])) {
             $i = $n;
             last;
         }

lib/Slic3r/Line.pm

@@ -17,16 +17,6 @@ sub new {
 sub a { $_[0][0] }
 sub b { $_[0][1] }
 
-sub id {
-    my $self = shift;
-    return $self->a->id . "-" . $self->b->id;
-}
-
-sub ordered_id {
-    my $self = shift;
-    return join('-', sort map $_->id, @$self);
-}
-
 sub coordinates {
     my $self = shift;
     return ($self->a->coordinates, $self->b->coordinates);

lib/Slic3r/Polyline.pm

@@ -45,11 +45,6 @@ sub is_serialized {
     return (reftype $self) eq 'SCALAR' ? 1 : 0;
 }
 
-sub id {
-    my $self = shift;
-    return join ' - ', sort map $_->id, @$self;
-}
-
 sub lines {
     my $self = shift;
     return polyline_lines($self);

lib/Slic3r/Surface.pm

@@ -73,18 +73,6 @@ sub offset {
     } $self->expolygon->offset_ex(@_);
 }
 
-sub add_hole {
-    my $self = shift;
-    my ($hole) = @_;
-    
-    push @$self, $hole;
-}
-
-sub id {
-    my $self = shift;
-    return $self->contour->id;
-}
-
 sub clipper_polygon {
     my $self = shift;