* xml filename into which to store the merged dataset. An HDF5 link master file with the same basename and extension ".h5" will be created that links into the source hdf5s.
* Append multiple HDF5 datasets, where each dataset contains the same
* setups but different timepoints.
*
* @param inputFilenames
* xml file names for input datasets
* @param outputXmlFilename
* xml filename into which to store the merged dataset. An HDF5 link master file with the same basename and extension ".h5" will be created that links into the source hdf5s.