New Quality section in GUI

lib/Slic3r/Config.pm

@@ -560,7 +560,7 @@ our $Options = {
         default => 70,
     },
     'extra_perimeters' => {
-        label   => 'Generate extra perimeters when needed',
+        label   => 'Extra perimeters if needed',
         tooltip => 'Add more perimeters when needed for avoiding gaps in sloping walls.',
         cli     => 'extra-perimeters!',
         type    => 'bool',

lib/Slic3r/GUI/Tab.pm

@@ -398,7 +398,7 @@ sub build {
         },
         {
             title => 'Vertical shells',
-            options => [qw(perimeters randomize_start extra_perimeters)],
+            options => [qw(perimeters)],
         },
         {
             title => 'Horizontal shells',
@@ -410,9 +410,13 @@ sub build {
                 },
             ],
         },
+        {
+            title => 'Quality (slower slicing)',
+            options => [qw(extra_perimeters avoid_crossing_perimeters)],
+        },
         {
             title => 'Advanced',
-            options => [qw(avoid_crossing_perimeters external_perimeters_first spiral_vase)],
+            options => [qw(randomize_start external_perimeters_first spiral_vase)],
         },
     ]);