The attempt to fix deadlocks when using exec() in a result slot by

delaying the signal emission in JobPrivate::handleResponse() some time
ago had a nasty side-effect on job pipelining, with server responses
possibly ending up with the wrong job. So, disable pipelining for now
until we have figured this problem out completely.

svn path=/trunk/KDE/kdepimlibs/; revision=1107729