Adding 1d Caress files to testdata (from XRay detectors)

A longer side project is to make Steca work with 1d Caress files from XRay detectors in the physicslab at MLZ, see Issue #91. So far this feature has been only tested with simplistic data files which show the I/O and data display works with this new files. What is still missing and should be added to testdata are files with real measurements. These will become available when Stress-Spec team will record them, most likely in the next couple of weeks.