Made different listeners and added method for adding meeting to
calendar.
Merge branch 'master' of https://github.com/Gruppe01/EXPHIL03 into gui-weekcalendar
Merge pull request #57 from Gruppe01/persistence-updatehandler

Fixed meeting and meeting storage
Made some changes. Removed duration field as it's really useful.
Merge pull request #58 from Gruppe01/gui-weekcalendar

Gui weekcalendar
Removed availableRooms from MySQL test