Currently MITK (f1953dbbb0) does not enable the following:
- .nii.gz, .hdr, .img, .img.gz file extensions not visible in File Open dialog,
leading to having to select "all files".
- .hdr, .img, .img.gz not visible in File Save dialog.
- In QmitkCommonFunctionality, file types ending in .gz simply don't work, resulting in the error message saying you must use .pic instead of .pig.gz.