3091 add -n to zlogin so its more compatible with rsh command line

*** 10,20 ****
  .\" include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable,
  .\" add the following below this CDDL HEADER, with the fields enclosed by
  .\" brackets "[]" replaced with your own identifying information:
  .\" Portions Copyright [yyyy] [name of copyright owner]
  .\" Copyright 2013 DEY Storage Systems, Inc.
! .TH ZLOGIN 1 "Sep 8, 2013"
  .SH NAME
  zlogin \- enter a zone
  .SH SYNOPSIS
  .LP
  .nf
--- 10,21 ----
  .\" include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable,
  .\" add the following below this CDDL HEADER, with the fields enclosed by
  .\" brackets "[]" replaced with your own identifying information:
  .\" Portions Copyright [yyyy] [name of copyright owner]
  .\" Copyright 2013 DEY Storage Systems, Inc.
! .\" Copyright (c) 2014 Gary Mills
! .TH ZLOGIN 1 "Jan 22, 2014"
  .SH NAME
  zlogin \- enter a zone
  .SH SYNOPSIS
  .LP
  .nf
*** 21,31 ****
  \fBzlogin\fR [\fB-CEQ\fR] [\fB-e\fR \fIc\fR] [\fB-l\fR \fIusername\fR] \fIzonename\fR
  .fi
  
  .LP
  .nf
! \fBzlogin\fR [\fB-EQS\fR] [\fB-e\fR \fIc\fR] [\fB-l\fR \fIusername\fR] \fIzonename\fR \fIutility\fR
       [\fIargument\fR]...
  .fi
  
  .SH DESCRIPTION
  .sp
--- 22,32 ----
  \fBzlogin\fR [\fB-CEQ\fR] [\fB-e\fR \fIc\fR] [\fB-l\fR \fIusername\fR] \fIzonename\fR
  .fi
  
  .LP
  .nf
! \fBzlogin\fR [\fB-nEQS\fR] [\fB-e\fR \fIc\fR] [\fB-l\fR \fIusername\fR] \fIzonename\fR \fIutility\fR
       [\fIargument\fR]...
  .fi
  
  .SH DESCRIPTION
  .sp
*** 121,130 ****
--- 122,142 ----
  Specifies a different \fIusername\fR for the zone login. If you do not use this
  option, the zone username used is "root". This option is invalid if the
  \fB-C\fR option is specified.
  .RE
  
+ .sp
+ .ne 2
+ .na
+ \fB-n\fR
+ .ad
+ .RS 15n
+ Redirect the input of \fBzlogin\fR to \fB/dev/null\fR.
+ This option is useful when the command running in the local zone
+ and the shell which invokes \fBzlogin\fR both read from standard input.
+ .RE
+ 
  .sp
  .ne 2
  .na
  \fB-Q\fR
  .ad