EdgeGrid::signed_distance_edges() to provide the pedal point.

Removed 20_print.t test.

xs/t/20_print.t

@@ -1,16 +0,0 @@
-#!/usr/bin/perl
-
-use strict;
-use warnings;
-
-use Slic3r::XS;
-use Test::More tests => 3;
-
-{
-    my $print = Slic3r::Print->new;
-    isa_ok $print, 'Slic3r::Print';
-    isa_ok $print->config, 'Slic3r::Config::Static::Ref';
-    isa_ok $print->placeholder_parser, 'Slic3r::GCode::PlaceholderParser::Ref';
-}
-
-__END__