Commits
Merging in latest from upstream (HDFFV/hdf5:refs/heads/develop) * commit '4cca93fcf9ddfbe06bb81b54a71a2ef723f94bf3': Bring new/updated tests from revise+chunks branch: flush1/flush2 update and flushrefresh test. (Also refactor of message send / wait code) Merge SWMR-related testing to existing tests. Bring over tweak for missing environment variable. Update CMake configuration files with SWMR accumulator changes. Add missing accumulator test. Merge SWMR-oriented accumulator tests from revise_chunks to develop. Bring Java SWMR changes from revise_chunks to develop branch