Add XSL script to convert a KConfigXT file into a D-Bus interface

description. This can be used to make application settings available
(and changeable) over D-Bus.

It's mostly a proof of concept for now to see if it helps us with
configuring Akonadi resource agents with external applications.

svn path=/trunk/KDE/kdepim/akonadi/libakonadi/; revision=772431