Only active users can log via federation support added.

#refs 1286
Merge branch 'branch-v2-1286-federation-login' of git://github.com/gmiotto/mconf-web into gmiotto-branch-v2-1286-federation-login

Conflicts:
	app/controllers/shibboleth_controller.rb
Several adjustments checking for active enrollment after PR #1

Have to first check if the shib variables are all there (shib.has_basic_info),
and only after that check for an active enrollment.

Also reorganized the tests because of this change and added 1 or 2 new ones.

refs #1286
Merge pull request #1 from gmiotto/branch-v2-1286-federation-login