[timed] Use correct rc-file in Qt5 version
[timed] Change systemd configuration to run as user
[timed] Notify systemd that timed is up and running

When timed is passed the command line switch --systemd, then
timed notifies systemd when it is ready.
[timed] Move voland to session bus to enable running as user
[timed] Add CAP_SYS_TIME required for settimeofday
[timed] Update data storage locations

Store settings and event queue files to HOME/.timed for both
Qt4 and Qt5 versions.