Fix some problematic regexps that mucked up extracting of embedded HTML tags in prettified text. Specifically, H1 and friends would not work, and CDATA sections in XHTML would be mangled.

Author: mikesamuel@gmail.com

src/prettify.js

@@ -611,13 +611,14 @@ window['_pr_isIE6'] = function () {
       '[^<]+'  // A run of characters other than '<'
       + '|<\!--[\\s\\S]*?--\>'  // an HTML comment
       + '|<!\\[CDATA\\[[\\s\\S]*?\\]\\]>'  // a CDATA section
-      + '|</?[a-zA-Z][^>]*>'  // a probable tag that should not be highlighted
+      // a probable tag that should not be highlighted
+      + '|<\/?[a-zA-Z](?:[^>\"\']|\'[^\']*\'|\"[^\"]*\")*>'
       + '|<',  // A '<' that does not begin a larger chunk
       'g');
   var pr_commentPrefix = /^<\!--/;
-  var pr_cdataPrefix = /^<\[CDATA\[/;
+  var pr_cdataPrefix = /^<!\[CDATA\[/;
   var pr_brPrefix = /^<br\b/i;
-  var pr_tagNameRe = /^<(\/?)([a-zA-Z]+)/;
+  var pr_tagNameRe = /^<(\/?)([a-zA-Z][a-zA-Z0-9]*)/;
 
   /** split markup into chunks of html tags (style null) and
     * plain text (style {@link #PR_PLAIN}), converting tags which are