Commits
Merge pull request #1515 in HDFFV/hdf5 from ~DEROBINS/hdf5_der:pread_vfd_squash to develop * commit '055208b71c573be3d4b1047b840d4d8b255bc25e': Minor tweak to CMake preadwrite entry. Updated sec2, log, and core VFDs to use pread/pwrite when available (can be controlled via a configure/CMake option)