Remove mention of block devices. Mention that entries under /dev

are managed by devfs(5).  Add cross-references.

Reviewed by:	ru

share/man/man7/hier.7

@@ -32,7 +32,7 @@
 .\"	@(#)hier.7	8.1 (Berkeley) 6/5/93
 .\" $FreeBSD$
 .\"
-.Dd August 16, 2004
+.Dd December 17, 2004
 .Dt HIER 7
 .Os
 .Sh NAME
@@ -73,13 +73,16 @@ comments apply
 (created by
 .Xr sysinstall 8 )
 .It Pa /dev/
-block and character device files
+device special files managed by
+.Xr devfs 5
 .Pp
-.Bl -tag -width ".Pa fd/" -compact
+.Bl -tag -width ".Pa net/" -compact
 .It Pa fd/
 file descriptor files;
 see
 .Xr \&fd 4
+.It Pa net/
+network devices
 .El
 .It Pa /dist/
 mount point used by
@@ -838,6 +841,8 @@ this document.
 .Xr whatis 1 ,
 .Xr whereis 1 ,
 .Xr which 1 ,
+.Xr fd 4 ,
+.Xr devfs 5 ,
 .Xr fsck 8
 .Sh HISTORY
 A