Fix for #49 ("Arrows keys in IE8...")

Fixes the issue by taking kuroir's suggestion of preventing
the default action. To be consistent with the rest of the
code, we do this by returning false in the event handler.

src/jquery.tokeninput.js

@@ -248,8 +248,8 @@ $.TokenList = function (input, url_or_data, settings) {
                         if(dropdown_item.length) {
                             select_dropdown_item(dropdown_item);
                         }
-                        return false;
                     }
+                    return false;
                     break;
 
                 case KEY.BACKSPACE: