Some minor changes
Done some minor changes in MVV Activity.
# add attribute "credits" to Exam.java
These changes are for startup wizard. AndroidManifest, strings and StartActivity files are modified.
Adding Token Management picture.
changed layout for cafeteria details
Cafeteria Layout: add separators between menus
Changes in list_layout_cafeteriamenue.xml
EndOfMerge
Refactored StartUpWizzard and CafeteriaActivity
Refactored Start-wizzard, changes some layout issues.
Adjusted error handling: no rights are now fetched and the user is 
informed.