Put CERN authentication into CARA

The main goal of this work is to be able to open up the limitation of CARA only being visible on the CERN network. It could now be exposed externally since it is protected behind a CERN username/password.

Note: Merging this requires a few tweaks to the cara.web.cern.ch. I wouldn't be surprised if there was a small downtime as a result. I've tested against http://test-cara.web.cern.ch - please take a look and confirm that you are requested to login, and once logged in, that your username is visible on the top right.