Logging in with SURF conext is possible
Moved authentication to a separate class

The BeeHub_Auth class now handles authentication and all actions associated
with it. This keeps beehub_run.php clean and makes responsibilities more clear.
Also, when authenticating with an unknown SURFconext ID, BeeHub will now look
if we have a local account with the same e-mail address and if so, links the
SURFconext ID automatically to it.
Merge remote branch 'origin/laura' into niek_vanalles

Conflicts:
	src/beehub.php
Fixed a bug introduced by the previous merge
Improved authentication procedures, especially when using SURFconext
Merge remote branch 'origin/laura' into niek_vanalles
groups changed
Merge remote branch 'origin/niek_vanalles' into laura
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