[Deploying Sakai] Kerberos provider and support for two-step authentication

[Seth Theriault]

Hello,

Matthew Buckett of Oxford has authored a bunch of changes in the 
KerberosUserDirectoryProvider to support two-step authentication 
by verifying service tickets. The changes are described in:

http://jira.sakaiproject.org/browse/SAK-10025

They were committed to trunk (future 2.7) yesterday:

http://source.sakaiproject.org/viewsvn?view=rev&revision=68832

In addition, the documentation has been brought up to date:

http://source.sakaiproject.org/viewsvn?view=rev&revision=68833

This new functionality must be explicitly enabled in 
sakai.properties.

Anyone using the Kerberos provider who is interested in this new 
functionality should review the JIRA and the appropriate 
documentation in the source code (README and docs/INSTALL.txt).

Seth