Towards working with evaluations.

Towards working with evaluations 2.

Towards working with evaluations 3.

Towards working with evaluations.

implemented getEvaluationSubmissions as a generator
Adds methods: getUser, removeForEvaluation, etEvaluationSubmissionStatus
Partial refactor of evaluationAPI stuff.
Adds class structure to evaluations.
Adds test for evaluation
Small fixes in evaluation parameters
Merge pull request #41 from larsssono/evaluation_API_implementation

Evaluation api implementation