Update man page, usage.
 [rsc] --rw-rw-r-- M 191333 glenda sys 1447 Sep 22 08:43 sys/man/4/ramfs
	/n/sourcesdump/2005/0922/plan9/sys/man/4/ramfs:4,21 - 
	/n/sourcesdump/2005/0923/plan9/sys/man/4/ramfs:4,19
	  .SH SYNOPSIS
	  .B ramfs
	  [
	- .B -i
	+ .B -Dips
	  ]
	  [
	- .B -s
	- ]
	- [
	- .B -p
	- ]
	- [
	  .B -m
	  .I mountpoint
	  ]
	+ [
	+ .B -S
	+ .I srvname
	+ ]
	  .SH DESCRIPTION
	  .I Ramfs
	  starts a process that mounts itself (see
	/n/sourcesdump/2005/0922/plan9/sys/man/4/ramfs:32,37 - 
	/n/sourcesdump/2005/0923/plan9/sys/man/4/ramfs:30,39
	  Initially the file tree is empty.
	  .PP
	  The
	+ .B -D
	+ option enables a trace of general debugging messages.
	+ .PP
	+ The
	  .B -i
	  flag tells
	  .I ramfs
	/n/sourcesdump/2005/0922/plan9/sys/man/4/ramfs:43,54 - 
	/n/sourcesdump/2005/0923/plan9/sys/man/4/ramfs:45,68
	  and 1 will be the network channel from
	  .I ramfs
	  to the client machine.
	+ .PP
	  The
	+ .B -p
	+ flag causes
	+ .I ramfs
	+ to make its memory `private'
	+ (see
	+ .IR proc (3))
	+ so that its files are not accessible through the debugging interface.
	+ .PP
	+ The
	  .B -s
	+ .RB ( -S )
	  flag causes
	  .I ramfs
	  to post its channel on
	  .B /srv/ramfs
	+ .RB ( /srv/ \fIsrvname\fR)
	  rather than mounting it on
	  .IR mountpoint ,
	  enabling multiple clients to access its files.
	/n/sourcesdump/2005/0922/plan9/sys/man/4/ramfs:55,69 - 
	/n/sourcesdump/2005/0923/plan9/sys/man/4/ramfs:69,74
	  However, it does not authenticate its clients and its
	  implementation of groups is simplistic, so
	  it should not be used for precious data.
	- .PP
	- The
	- .B -p
	- flag causes
	- .I ramfs
	- to make its memory `private'
	- (see
	- .IR proc (3))
	- so that its files are not accessible through the debugging interface.
	  .PP
	  This program is useful mainly as an example of how
	  to write a user-level file server.
 [rsc] --rw-rw-r-- M 191333 glenda sys 15950 Sep 22 08:43 sys/src/cmd/ramfs.c
	/n/sourcesdump/2005/0922/plan9/sys/src/cmd/ramfs.c:172,178 - 
	/n/sourcesdump/2005/0923/plan9/sys/src/cmd/ramfs.c:172,178
	  		defmnt = 0;
	  		break;
	  	case 'm':
	- 		defmnt = ARGF();
	+ 		defmnt = EARGF(usage());
	  		break;
	  	case 'p':
	  		private++;
	/n/sourcesdump/2005/0922/plan9/sys/src/cmd/ramfs.c:887,892 - 
	/n/sourcesdump/2005/0923/plan9/sys/src/cmd/ramfs.c:887,892
	  void
	  usage(void)
	  {
	- 	fprint(2, "usage: %s [-is] [-m mountpoint]\n", argv0);
	+ 	fprint(2, "usage: %s [-Dips] [-m mountpoint] [-S srvname]\n", argv0);
	  	exits("usage");
	  }
 [sys] --rwxrwxr-x M 191333 glenda sys 89822 Sep 22 23:10 386/bin/ramfs
	/sys/src/cmd/ramfs.c:main
	/sys/src/cmd/ramfs.c:usage
	/sys/src/libc/port/rune.c:chartorune