hdf5_ep

Addressed HDFFV-10661
Description:
    - Fixed a bug triggered by tests in chunk_info.c.  The returned value
      from a callback function was not checked in H5EA_iterate(), H5FA_iterate(),
      and H5D__none_idx_iterate().  This oversight caused a callback function
      to continue iterating even though it's supposed to stop.  Vailin confirmed.
    - Addressed review comments and made various improvements on the tests.
Platforms tested:
    Linux/64 (jelly)
    Linux/64 (platypus)
    Darwin (osx1010test)