Added default top margin of 1px for icons.

less/sprites.less

@@ -25,6 +25,7 @@
   background-image: url("@{iconSpritePath}");
   background-position: 14px 14px;
   background-repeat: no-repeat;
+  margin-top: 1px;
 }
 
 /* White icons with optional class, or on hover/active states of certain elements */