Added state for providing information for a single teaching material
Added an action for fetching a single teaching material
Added categories and categoriesInfo state
Added comments for newly added functions.
Changed categories state to Map<Integer,Category>
removed CategoryInfo-State
Added DAO-binding in BasicModule for Categories
Edited View to use the new States of BMViewModel.
Merge remote-tracking branch 'upstream/develop' into issue#200-201
Added doUpdateCategory method.
Merge pull request #211 from Junkern/issue#123,#201

Issue#123,#201