Added functionality to remove the employee shift by using the unique shift id to both the server and client side.

This reverts commit c3032b36

Fixed bugs with that caused in consistencies with message sending between client and server. All employee data should be updated to all clients when employee data is modified in the database. The client should have an updated copy of employee information.

Changed schedule and staff class so that the connection is made from the model and passed to the staff and schedule class.