Method to open an URI in the user default web browser. It uses the Java
Desktop API on Windows and Gnome environment and xdg-open on other
platforms (non-gnome linux distribution for example).
A Bug report have been opened in 2006 so that java.awt.Desktop can
support all environments but it is not fixed yet :
http://bugs.sun.com/view_bug.do?bug_id=6486393 this utility method should
be removed when the bug is fixed.