Implement tinting by icon content (issue #638; thanks @heisenbug)

src/tint2conf/properties.h

@@ -203,6 +203,8 @@ enum {
     bgColBorderSidesBottom,
     bgColBorderSidesLeft,
     bgColBorderSidesRight,
+    bgColFillWeight,
+    bgColBorderWeight,
     bgNumCols
 };
 
@@ -211,7 +213,7 @@ extern GtkWidget *current_background, *background_fill_color, *background_border
     *background_fill_color_over, *background_border_color_over, *background_gradient_over, *background_fill_color_press,
     *background_border_color_press, *background_gradient_press, *background_border_width, *background_border_sides_top,
     *background_border_sides_bottom, *background_border_sides_left, *background_border_sides_right,
-    *background_corner_radius;
+    *background_corner_radius, *background_border_content_tint_weight, *background_fill_content_tint_weight;
 
 // gradients
 enum { grColPixbuf = 0, grColId, grColText, grNumCols };