remove OrderedDictionary from LASFile
remove OrderedDictionary from LASFile

Needs some rigorous thinking and work on LASFile.__setattr__ and
__getattr__ and __setitem__ and __getitem__ in order to be able to
cope with LAS 3.0

Nearly there - and then tests.

kwinkunks/lasio,kinverarity1/las-reader,kinverarity1/lasio