Now agents no longer run in seperate processes per se, we need to deal

with the fact the QDBusConnection is not thread save.

First step: Add the dbusconnectionpool (copied from kdelibs/nepomuk/core.
Next step: Replace all QBusConnection::sessionBus() with calls to the
           connection pool,

svn path=/trunk/KDE/kdepimlibs/; revision=1176361