Commits
Merging in latest from upstream (HDFFV/hdf5:refs/heads/hdf5_1_8) * commit '90b2126a38fd73ccef9aec823eaec372295d1270': Archive RELEASE.txt from HDF5 1.8.19 in HISTORY-1_8.txt. Clear entries from New Features and Bugs Fixed sections of RELEASE.txt. Revert change for temporary testing.