bind Properties as lazy singleton
change modifiers of States from private to public final
added helper methods for Entity instantiation
added test methods for state testing
added cascading options
fixed Logger initialisation
use a category when creating TeachingMaterial
added further tests
simplified test
added helper methods for creating a user
use new helper methods in TestUtils.java
fixed bug concerning login state with Properties singleton
added helper method for creating a SchoolYear in the future
added further tests
added further tests
added further (failing) tests
cleanup
Merge pull request #697 from davherrmann/issue#692

Issue#692: add JUnit tests for SettingsViewModel