Work with .h5 files

Diffraction images from Eiger detectors are written as .h5 files (NeXus format), in which multiple images may be compressed into one file. HKL-2000 release 714 can process .h5 files directly, thereby sidestepping the need to extract images manually and convert them into individual .cbf files. From the user's perspective, processing is handled just like any other file format (.cbf, .img, etc).