Fixes #66, #56, Log notices for exceptions that we can catch like being unable to receive a message or a user not being a VO member.
Partly fixes issue #70.
Fixes issue #70 "crashes hard when SP requests HTTP-Artifact binding", ignore requests for bindings we don't support.
Fixes issue #69 "WAYF: when no results found, pressing enter advances to the first IdP"
Remove the previously selected IdP every time the Idps are re-displayed.
Fixes issue #68, reverts fix for issue #58 "SP using transparent endpoint should get engine as issuer"
Fix english language string to add missing variable.

Closes #45
Fixes issue #62 "Sending debug email fails with call to undefined method", fixed fatal error on call to removed layout method
Fixes issue  #65 "better error when missing or wrong certificate in sp metadata", recgnize that a certificate may not have been set and let SSP generate the error for us.
Added release notes for 4.1.6.
Merge branch 'release/4.1'