Master Key Migration Project

Master Key Migration Project

Commit for the Master Key Migration Project.
http://k5wiki.kerberos.org/wiki/Projects/Master_Key_Migration

This commit provides the ability to add a new master key (with an
enctype differing from the current master key) to the master key
principal and stash file and then migrate the encryption of existing
principals long term keys to use the new master key.  In addition
deletion of master keys is provided.

ticket: 6354

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@21844 dc483132-0cff-0310-8789-dd5450dbe970