Added selection and popup for <pre> tags within wikitext. Also fixed more bugs found in the HTML paragraph parser (mostly self-closing tags e.g. <hr />).
.mcePageBreak {display:block;border:0;width:100%;height:12px;border-top:1px dotted #ccc;margin-top:15px;background:#fff url(../img/pagebreak.gif) no-repeat center top;}