This is a patched version that drops pwd logic from load_raw_data_with_mhd and assumes that
meta_dict['ElementDataFile'] always contains an absolute filepath. For details see
yanlend#6.
Reading and writing .mhd files in python, extension from https://sites.google.com/site/pjmedphys/
Extended functionality:
- more datatypes supported
- handles 'ElementNumberOfChannels'
- allows to write meta-information