add / delete study -> save instead of delete

[buddekai]

After clicking on "add study", you can add information for a new study. It is automatically saved. The "delete" button does not make sense in my opinion because you can only delete the study immediately after having entered the information. Therefore, I would prefer to have a "save" button instead that saves the information only when clicking on that button. I do not know right now if and where a user should be able to delete an entire study.