First draft of a self-updating collection model. This is work in

progress and far from usable, but please review and let me know if it is
going at least into the right direction ;-)

Also included is a very ugly test program that generates a large
collection tree and changes it randomly.

CCMAIL: kde-pim@kde.org

svn path=/trunk/KDE/kdepim/libakonadi/; revision=503536