Add Description fields to PerformanceEvaluation, Evaluation, EvaluationObjective and EvaluationElement

In the "learning through ownership" (LTO) project at Mesquite ISD, we have values that we are trying to use for EvaluationObjective.Title that are longer then the 50 allowed characters. Although it is not a problem for us I could also see this happening with Evaluation and PerformanceEvaluation.  It is not an issue for EvaluationElement.

I would consider adding optional fields EvaluationObjective.EvaluationObjectiveDescription, Evaluation.EvaluationDescription,  and PerformanceEvaluation.PerformanceEvaluationDescription that are 255 characters long.

cc Itzel.Torres