hdfview

Merge pull request #189 in HDFVIEW/hdfview from ~JHENDERSON/hdfview:master to master

* commit '6d8db87ce0bd40071b4e3a2fe017d6ff598fdf95':
  Correct indexing for bitfields as a base type
  Fix CompoundDataProvider for most datatypes
  Add support for data transpose/reshaping to array type datasets
  Display "Null" in cell value field for null values
  Fix ArrayDataProvider indexing