change position of var in dropdown + cleanup makefile vars

docs/assets/js/bootstrap-dropdown.js

@@ -40,10 +40,14 @@
 
   , toggle: function (e) {
       var $this = $(this)
-        , selector = $this.attr('data-target')
         , $parent
+        , selector
         , isActive
 
+      if ($this.is('.disabled, :disabled')) return
+
+      selector = $this.attr('data-target')
+
       if (!selector) {
         selector = $this.attr('href')
         selector = selector && selector.replace(/.*(?=#[^\s]*$)/, '') //strip for ie7