public ActionResult Criar(Turma model,FormCollection form)
        {
            Guid profId = Guid.Empty;

            if (Guid.TryParse(form["Professores"], out profId))
                model.Professor = repositorioProfessor.RetornaPorID(profId);
            model.Professor.Status = ProfessorStatus.Alocado;

            repositorioTurma.Salvar(model);

            return RedirectToAction("Index");
        }
        public ActionResult Editar(Turma model, FormCollection form)
        {
            Guid profId = Guid.Empty;

            if (Guid.TryParse(form["Professores"], out profId) && model.Professor.ID != profId)
                model.Professor = repositorioProfessor.RetornaPorID(profId);

            repositorioTurma.Salvar(model);

            return RedirectToAction("Index");
        }
        public ActionResult Matricular(Turma model)
        {
            repositorioTurma.Salvar(model);

            return RedirectToAction("Index");
        }
        public ActionResult Delete(Turma model)
        {
            repositorioTurma.Remover(model);

            return RedirectToAction("Index");
        }