Interfaces of Detector and Chopper now return const references to
containers
PoldiAutoCorrelationCore now does some basic logging
Fixed PoldiProjectAddFile so it does not crash when run multiple times
Updated POLDI calibrated parameters in instrument file
Added more unit tests for PoldiAutoCorrelationCore

Only calculate() and getRawCorrelatedIntensity() are missing now. For
the moment they have to be covered by a system test that compares the
algorithm's results for known input to a known reference.
Added documentation to setCountData method of PoldiAutoCorrelationCore