[9fans] remote access to fossil console

[jmk@plan9.bell-labs.com]

Here's something I did last week to get remote access to the fossil
console using consolefs to our server called 'ehime':

1) you need a consoledb file, say /lib/ndb/consoledb-ehime:
	% cat consoledb-ehime
	group=sys
		uid=jmk
		uid=...
	console=ehime-fs dev=/srv/fscons
		gid=sys
	%

2) add a case to /bin/C to select the correct server:

	...
	switch($1){
	case ehime-fs
		server=ehime
	case *
		# look for server in /lib/ndb
		server=`{ndb/query sys $1 console}
		switch($server){
		case ''
			echo C: unknown console server for $1
			exit 1
		}
	}
	...

3) add startup code for consolefs in /bin/cpurc.ehime:

	...
	# start the remote fs console server
	if(test -e /srv/fscons)
		aux/consolefs -c /lib/ndb/consoledb.ehime
	...

Now we can 'C ehime-fs' just like we can for the serial consoles
of the servers in the machine room.

I changed consolefs last week not to present the status and ctl files
for remote consoles if the underlying device doesn't support them, but
this will work without that update to consolefs.