reenable old xfce styles in 3.20 until we can rewrite them.

src/gtk-3.20/scss/_widgets.scss

@@ -34,6 +34,6 @@
 @import "apps/nemo";
 @import "apps/panel";
 @import "apps/synaptic";
-//@import "apps/xfce";
+@import "apps/xfce";
 @import "apps/unity";
 @import "apps/lightdm";

src/gtk-3.20/scss/apps/_xfce.scss

@@ -5,7 +5,7 @@
 ****************/
 
 @include exports("xfce") {
-    /*XfceHeading {
+    .XfceHeading {
         margin: 0;
         padding: 0;
         border: 0;
@@ -20,6 +20,5 @@
         font: inherit;
 
         button { @extend %panelbutton; }
-    }*/
-
+    }
 }