* "Simultaneous and equivalent" Read-Write and Write-Only channels for
file I/O.
* Only supports drivers with the H5FD_FEAT_DEFAULT_VFD_COMPATIBLE flag for
now, preventing issues with multi-file drivers.
Add Mirror VFD to library.
* Write-only operations over a network.
* Uses TCP/IP sockets.
* Server and auxiliary server-shutdown programs provided in a new directory,
`utils/mirror_vfd`.
* Automated testing via loopback ("remote" of localhost).
