officially drop support for offset on thumbnails since it breaks BC

less/tests/css-tests.css

@@ -36,13 +36,15 @@ h4 {
 
 
 /* Fluid grid */
+.fluid-grid {
+  margin-bottom: 45px;
+}
 .fluid-grid .row {
-  height: 60px;
+  height: 40px;
   padding-top: 10px;
   margin-top: 10px;
-  color: #fff;
+  color: #ddd;
   text-align: center;
-  background-color: #eee;
 }
 .fluid-grid .span1 {
   background-color: #999;

less/tests/css-tests.html

@@ -632,6 +632,23 @@
   <h1>Thumbnails</h1>
 </div>
 
+<h4>Default thumbnails (no grid sizing)</h4>
+<ul class="thumbnails">
+  <li class="thumbnail">
+    <img src="http://placehold.it/260x180" alt="">
+  </li>
+  <li class="thumbnail">
+    <img src="http://placehold.it/260x180" alt="">
+  </li>
+  <li class="thumbnail">
+    <img src="http://placehold.it/260x180" alt="">
+  </li>
+  <li class="thumbnail">
+    <img src="http://placehold.it/260x180" alt="">
+  </li>
+</ul>
+
+<!-- NOT CURRENTLY SUPPORTED
 <h4>Offset thumbnails</h4>
 <ul class="thumbnails">
   <li class="span3 offset3">
@@ -650,6 +667,7 @@
     </a>
   </li>
 </ul>
+-->
 
 <ul class="thumbnails">
   <li class="span3">