[7u] Request for approval for CR 8014196: ktab creates a file with zero kt_vno

[Weijun Wang]

Hi All

This is a request to backport a jdk8 fix into jdk7u.
   http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8014196

ktab.exe in Java could create a ktab file that is not recognizable by 
3rd party kerberos tools.

The fix is already included in jdk8 as:

   http://hg.openjdk.java.net/jdk8/tl/jdk/rev/6816afd70a68
   Reviewed-by: valeriep

The patch for jdk7u is identical to the one in jdk8.

The fix is low-risk, and isolated. new regression test added. Existing 
tests also run fine.

Thanks
Weijun