Remove files that have been checked in by mistake

The nimsoft and manifests directory have been empty or the scripts have
been unusable, so remove them from the repository.
Add helper script restart_probe.sh

Every configuration change of a probe needs a restart of the effected
probe. Unfortunately a probes cannot be started directly from the
commandline because they would not appear in the infrastructure manager
and may start with a wrong environment. A probe has to be started
through the controller probe.

The controller probe has an API to stop and start a specific probe but
this API only works with a valid adminsitrative nimsoft account and a
password - things you do not want to expose on every nimsoft robot.

The helper script now uses a different way: It will simply send a
SIGTERM to the specified probe and will wait for it to die. Once the
probe is down we wait for the controller to restart the probe.