Mention fdescfs(5) and why it might be useful.
Mention fdescfs(5) and why it might be useful.

MFC after:	1 week
Suggested by:	Stephen Montgomery-Smith <stephen at math dot missouri dot edu>

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase