Redesign of ImportView
Added state for providing information for a single teaching material
Added an action for fetching a single teaching material
Refactored upload receiver into the import view
Put input stream from the upload to csv reader
Deleted CSVUploader
Deleted unnecessary CSVHandler method.
Changed CSVTest due to changes of the CSVHandler api.
Zugriff auf alle nicht erhaltenen BorrowedMaterials implementiert
Persistierung des Eltern-Objekts wieder einkommentiert.
Merge pull request #197 from davvitt/issue#194-getUnreceivedBM

Zugriff auf alle nicht erhaltenen BorrowedMaterials implementiert
Removed createParentObjectsFromCSV.
Parent objects are created together with student objects now since all
parent information are in the same csv as the student information.
Added categories and categoriesInfo state
Deleted test method that tested the creation of parent objects.
Added try catch to check parent objects creation.
Added comments for newly added functions.
Added first version of StudentMaterialSelector.
Persist students in importViewModel.
Added null check for parent objects.
Changed categories state to Map<Integer,Category>
improved logger settings - added second configuration for tests