tweaks and increase specificity of pills and active classes

lib/tabs-pills.less

@@ -182,7 +182,7 @@
 
 // Pills
 .pills {
-  a {
+  > a {
     padding: 0 15px;
     margin: 5px 3px 5px 0;
     line-height: 30px;
@@ -195,7 +195,7 @@
       background-color: @linkColorHover;
     }
   }
-  .active a {
+  .active > a {
     color: @white;
     text-shadow: 0 1px 1px rgba(0,0,0,.25);
     background-color: @linkColor;