Inefficient internal content(Element) method

[lukaseder]

There's an internal content(Element) method with a TODO that does not yet have an issue associated with it:

// TODO: Check this code's efficiency
String name = element.getTagName();
return Util.toString(element).replaceAll("(?s)^<" + name + "(?:[^>]*)>(.*)</" + name + ">$", "$1");

This is very obviously inefficient. We cannot cache the regular expression, but we can traverse the string without resorting to regexes, as the regex logic is rather simple.