Merge pull request #515 in HDFFV/hdf5 from ~VCHOI/my_hdf5_fork:develop to develop
* commit '54dff331778a660824961fdf6359e4eae998a13c':
Incorporate additional code changes for the H5DOread_chunk patch from GE Heathcare (HDFFV-9934) This is the similar set of changes that was checked in to 1.8 branch: 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 platypus, ostrich, kituo, mayll, osx1010test, moohan, quail, emu.
