Merge pull request #485 in HDFFV/hdf5 from ~VCHOI/my_hdf5_fork:hdf5_1_8 to hdf5_1_8
* commit '8c2d4c354413d4f3578aa30cf28ee4c4f5c137cf':
Incorporate additional code changes for the H5DOread_chunk patch from GE healthcare (HDFFV-9934) Modifications made based on pull request (#485) comments.
Incorporate additional code changes for the H5DOread_chunk patch from GE healthcare (HDFFV-9934) Incorporate the code changes that were missing from the original patch: (1) Additional tests in hl/test/test_dset_opt.c (2) Fix in src/H5Dchunk.c for direct access when an entry is in chunk cache but not dirty Tested on playtpus, ostrich, kituo, mayll, osx1010test, quail, emu.
