make component animations work cross browsers with opacity mixin, restore float on thumbnails > li

less/component-animations.less

@@ -2,17 +2,17 @@
 // --------------------
 
 .fade {
-  opacity: 0;
+  .opacity(0);
   .transition(opacity .15s linear);
   &.in {
-    opacity: 1;
+    .opacity(100);
   }
 }
 
 .collapse {
-  position:relative;
+  position: relative;
   height: 0;
-  overflow:hidden;
+  overflow: hidden;
   .transition(height .35s ease);
   &.in {
     height: auto;

less/thumbnails.less

@@ -14,6 +14,7 @@
 
 // Float li to make thumbnails appear in a row
 .thumbnails > li {
+  float: left; // Explicity set the float since we don't require .span* classes
   margin-bottom: @baseLineHeight;
 }