Add openid connect support

Add minor changes to the code to support the apache module
mod_auth_openidc (https://github.com/pingidentity/mod_auth_openidc)

Also add documention on how to setup mod_auth_openidc for
SP federation.

implements: bp openid-connect

Change-Id: Ia48e94905de0a9ee0e3c8d4f007075cba6e7e770
Additional debug logs for federation flows

Adds debug logging for federation flows, specifically around the
mapping functions.

Change-Id: I40ed26173937d2b6b74f6228cf8e61373ea88b86
Closes-Bug: #1389586
Merge "Add openid connect support"
Merge "Additional debug logs for federation flows"