Catches ActiveRecord::NotFound to reroute to 404
Adds exceptions for role access level
Hide non-approved challenges
Redefined visible states a little
Fixed test
Pre-merge commit
Merge branch '404routing' into hotfix
Friendlier error messages
Merge branch 'master' of github.com:boersmamarcel/challengesplatform into 404routing
Adds custom exceptions
Fixes acces to sign up page
Merged branches & set error messages
Conflicts:
	app/controllers/application_controller.rb
Removed "signed in succesfully" messages
Merge pull request #141 from boersmamarcel/404routing

Custom exceptions
Renamed scope to more descriptive name
Merge pull request #144 from boersmamarcel/hotfix

Renamed scope to more descriptive name
Merged with master again