[krbdev.mit.edu #7476] updated manual page for kvno

[Mark Pröhl via RT]

 >Submitter-Id:  mark at mproehl.net
 >Originator:    root
 >Organization:
         <organization of PR author (multiple lines)>
 >Confidential:  no
 >Synopsis:      kvno manual page does not document -k and -C
 >Severity:      non-critical
 >Priority:      low
 >Category:      krb5-doc
 >Class:         doc-bug
 >Release:       1.12-prerelease
 >Environment:
         <machine, os, target, libraries (multiple lines)>
System: Linux centos63 2.6.32-279.14.1.el6.x86_64 #1 SMP Tue Nov 6 
23:43:09 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
Architecture: x86_64

 >Description:
         kvno manual page does not document -k and -C
 >How-To-Repeat:
         man kvno
 >Fix: attached