hdfview

Merge pull request #111 in HDFVIEW/hdfview from ~JHENDERSON/hdfview:master to master

* commit '2189df0449e0375dc6b9eebfa818564c5c0e0ad1':
  Check that a dataset's datatype isn't null when setting its image
  Fix for HDFView-75
  HDF4 - only open w/ write permission if fileformat isn't read-only
  Make sure log is not used when classes are statically instantiated
  Missing File from UI tests fixes
  Fix for HDFVIEW-178 - issue with opening files from cmd line
  Updates to have HDFView open read-only by default