Merge pull request #50 in HDF5VOL/daos-vol from ~NFORTNE2/daos-vol:master to master
* commit 'a5661e2e03b6703ad59db42d28a275bfc7b79f07':
Modify H5_daos_addr_to_oid to check for HADDR_UNDEF
Switch to using DAOS to allocate object IDs, via daos_cont_alloc_oids. Encode DAOS private bits into the haddr_t form of OIDs. Note that this places an upper limit of 30 bits of object IDs before API functions that use haddr_t stop working. H5Oopen also has this restriction for now (though it will disappear once tokens are implemented).
