Broad refactor to improve customization of purchase order form etc.

* add dropdown alternative for autocomplete renderer
* auto-enhance some common dropdowns
* refactor new purchase batch, order form view/templates

tailbone/static/js/tailbone.js

@@ -147,12 +147,17 @@ $(function() {
     });
 
     /*
-     * Fix buttons.
+     * enhance buttons
      */
     $('button, a.button').button();
     $('input[type=submit]').button();
     $('input[type=reset]').button();
 
+    /*
+     * enhance dropdowns
+     */
+    $('select[auto-enhance="true"]').selectmenu();
+
     /* Also automatically disable any buttons marked for that. */
     $('a.button[disabled=disabled]').button('option', 'disabled', true);