Merge pull request #53 from Gruppe01/persistence-updatehandler

Persistence updatehandler
Made some methods for logic
Merge pull request #54 from Gruppe01/persistence-updatehandler

Fixed name pattern
Merge branch 'master' of https://github.com/Gruppe01/EXPHIL03 into gui-weekcalendar
Merge pull request #55 from Gruppe01/persistence-updatehandler

Fixed client server communication
Made some logic to the different buttons.
Merge pull request #56 from Gruppe01/gui-weekcalendar

Gui weekcalendar