[DynareDev] Unit Tests for Dataset

Dear Stéphane,

I think the unit test for loading mat-files in the new interface needs to be relaxed. It currently loads all variables in a datafile and checks for correct dimensions. This implies that no auxiliary information is allowed to be stored in the mat-file as it will results in errors. I think this is overly restrictive. We should only check for consistency of the declared observable variables and not care about other contents of the m-file. See the attached example file for a display of the problem.

Best,

Johannes