revert to negative margin on grid row

lib/scaffolding.less

@@ -73,13 +73,10 @@ a {
 // -----------
 // To customize the grid system, bring up the variables.less file and change the column count, size, and gutter there
 .row {
+  margin-left: @gridGutterWidth * -1;
   .clearfix();
 }
 
-[class*="span"]:first-child{
-  margin-left: 0;
-}
-
 // Find all .span# classes within .row and give them the necessary properties for grid columns 
 // (supported by all browsers back to IE7)
 // Credit to @dhg for the idea

lib/thumbnails.less

@@ -8,7 +8,7 @@
 }
 .thumbnails > li {
   float: left;
-  margin: 0 0 20px 20px;
+  margin: 0 0 @baseLineHeight 20px;
 }
 .thumbnail {
   display: block;