SAK-28125

Add a feature to send a BlowFish encrypted session to particularly well-trusted
LTI tools to allow them to ace "as user" when accessing Sakai URLs like "/direct"
The new field is "ext_sakai_encrypted_session"



git-svn-id: https://source.sakaiproject.org/svn/basiclti/trunk@315720 66ffb92e-73f9-0310-93c1-f5514f145a0a