Existing HTML links and images are broken by the WYSIWYG editor

We should not break existing img and a tags when they come from the wiki editor.

Example

<a href="http://www.mozilla-europe.org/fr/products/firefox/"
title="Get Firefox - Web browsing redefined."><img
src="http://www.firefox.fr/boutons/getfirefox_large2.png"
width="178" height="60" border="0" alt="Get Firefox"></a>

This code in the wiki editor. Edit with wysiwyg and save.
The result is broken.

The same strategy with the id="manual_" can be used.