Convert a relative url to an absolute url base on a base url.

Convert an html doc's urls from relative to absolute base on a base url.

Convert text to html Example: text := ` First line Second line Third line <b id="html">line contains html</b> ` html := Text2Html(text) now html will be: <p>First line</p><p>Second line<br>Third line</p><p>&lt;b id=&#34;html&#34;&gt;line contains html&lt;/b&gt;</p> */.