Make the homepage bg a little darker, so that it is not identical with the bg of sidebar

h/css/common.scss

@@ -601,6 +601,10 @@ blockquote {
   background: url("../images/noise_1.png");
 }
 
+.dark-noise {
+  background: url("../images/dark_noise_1.png");
+}
+
 
 //KNOCKOUT///////////
 //Provides a knockout background