Commits
Merge pull request #177 in HDF5VOL/daos-vol from ~NFORTNE2/daos-vol:docs to master * commit '5b27753ce65a096f9596c34ba5067ba2e158d521': Update users_guide.pdf. Add tests for H5Aexists(), H5Ocopy(), and H5Orefresh(). Update async users' guide section to reflect future id changes. Update API and feature level support tables. Add text about close routines to async section. Add user's guide section on asynchronous I/O (function reference still needs to be updated).