Unbreak generation of hypertext references declared inside <body>.
Convert <url href="...">...</url> used inside <body> tag into <a></a> form.
This is required because <body> content being passed into generated
html as is (using select="child:node()"), and as result href's declared
via <url></url> are passed into generated html unmodified. Browser
ignore unknown tags, so we resulted up with incorrectly rendered hrefs.