The cleaner is started if a tape could be in the drive after a session crashed. This depends on the previous
sesion state.
If a cleaner crashes, the next session will put the drive down.
The sessions do not fully report their states yet.

The Shutdown state can only be used internally by the DriveHandler after process exit.

Added one second sleeps when uncaught exceptions show up to avoid fast looping in the presence of bugs.

Added exception lauching for sqlite call that returned NULL in some cases (DB might have been corrupted).

The drive will put itself back down as long as a tape is detected in the drive.

This will allow the simplification of data structures and the enventual removal of the castor namespace.

Removed DataTransferSessionEmptyOnVolReq unit test which now locks (sessions now loop until they schedule).

Moved the jump destination after not scheduling to take up/down status into account on next iteration.

The new configuration parameter has a compile time defaul (previous did not).

Unified and extended the logging.
Added end of session logs.

The detection is now done when creating the agent entry,
which happen before constructing the scheduler.

Also improved some exceptions for to-be implemented functions.

Found in case where by default docker does not install documentation files.