Merge pull request #2033 in HDFFV/hdf5 from ~NFORTNE2/hdf5_naf:public_spi to develop
* commit 'db6eab893e5f027f0b535316e0e7a9abe9ff8619':
Implement public H5Sselect_project_intersection(). Updated internal algorithm to (optionally) avoid sharing selection data structures. Tested internal code (including with valgrind) by setting VDS code to avoid sharing selection, has since been changed to share selection for performance, so this code is not yet tested in regression tests. API has not been tested.
