Added isAdmin functionality

Includes checks for isAdmin for problems and a handlebars template helper
No longer send userId when checking for submitted answer to a problem

Removed ability to call the checkAnswer function on the server with a custom
userId. Could be misused to decrement another users possible score for a single
problem
Removed unused test code for running submitted code files
Viser nå svaret på correct besvarte oppgaver, uten noe sikkerhet.
Både checkAnswer og revealAnswer bruker nå serverside check på innlogget brukerId, for securityyyy
Meeerge