Implement University Log-In

[GHLasse]

We will need to implement the university log-in to replace the current one. This means linking to the university log-in page, interpreting the result and changing any last references to the user table to use the staff table and the current user returned by the uni-log-in instead.

[GHLasse]

This is required to do #115 and #72 as well as #78

[GHLasse]

Useful Server variables we get to know: [MELLON_cn] = university username [MELLON_uid] = university username [MELLON_mail] = user email as used for outgoing emails [MELLON_eduPersonPrincipalName] = user email original [MELLON_sn] = user surname [MELLON_urn:oid:2_5_4_42] = user first name [AUTH_TYPE] = Mellon [MELLON_NAME_ID] = unique person identifier string (?)

[GHLasse]

I managed to implement the log-in and basic authentication things - users are identified through their email and are logged in as a "customer" if not in our staff list.