This includes only the icons actually used or intended to be used
in the backend. Please note that unfortunately, some class names
have changed. Also some icons have been exchanged.
This works for entries, comments and media items including changing
the multidelete marker. Needs to be tested with Karma plugin which
uses the old function as well.
Also moved reference to serendipity_editor.js before the closing
body element. This way, jQuery's $(document).ready() equals
$(window).load(), so we don't have to use that any longer.