...which updates RFC 2396, removes the requirement that the base URI's path
starts with a slash, and clarifies how to treat excess "." and ".." segments.

This nicely allows handling of those odd vnd.sun.star.Package URLs as intended
now, so that making <foo> absolute relative to base URL
<vnd.sun.star.Package:Pictures/bar> yields <vnd.sun.star.Package:Pictures/foo>
instead of provoking a MalformedUriException.

Change-Id: Ice84303a57698a2c05d3a45541fe78b67450fa3c