osx: More theme tweaks

osx/gtkrc

@@ -229,20 +229,21 @@ style "treeview" = "default"
 
     font_name = "Lucida Grande 12"
 
-    engine "xamarin" {
-        roundness = 0
-        gradient_shades     = {1.0, 1.0, 1.0, 1.0}
-        glazestyle = 1
+    engine "quartz" {
     }
 }
 
-style "tree-header" = "wide"
+style "tree-header"
 {
+    ythickness = 0
     bg[NORMAL] = "#f2f2f2"
+    font_name = "Lucida Grande 11"
 
-    engine "xamarin" {
-        listviewheaderstyle = 3
-        separatorstyle = 1
+    GtkWidget::focus-line-width = 0
+    GtkWidget::draw-border = { 1, 1, 1, 1 }
+    GtkButton::inner-border = { 3, 3, 1, 3 }
+
+    engine "quartz" {
     }
 }