Changelog A.E.: Update 5

General
- renamed Carsharing.cs into CarsharingSystem.cs
- new Class Branch.cs (old Carsharing.cs)

- moved CreateInstances() and ReloadInstances to CarsharingSystem.cs
- fixed Bug in CreateInstances() and adjusted InsertLendedCars() to make
it work together propertly

- edited name conventions for methods

Car.cs

- new attribute "assignedBranchNo"
- modified Constructor with the new attribute