refer the reader to the detailed information in section 5,
remove the mount_* man pages for those file system. mount_std(8)
to cover all of the file systems it is currently being used
to mount.
mount_{devfs, fdesc, kernfs, procfs}.8 are now
MLINKS to mount_std.
mount_* programs. While we're at it, collapse the four now-identical
mount programs for devfs, fdesc, kernfs, and procfs into links to
a new mount_std(8) which can mount any really generic filesystem
such as these when called with the appropriate argv[0].
Also, convert the mount programs to use sysexits.h.
