DAOManager
Updater
Added Updater to Core and ServiceFactory
Prevent circular references
Set Exercise.downloaded attribute on update
Refactor UI to use the new API
Deprecate CourseFetcher and ExerciseFetcher
Filter out already downloaded exercises
Fixed merge conflict
Initial tests for Updater
Merge branch 'DEV' of github.com:tmc-eclipse/tmc-eclipse into DEV