#207 adder method support for target collections and unit test
#207 JavaDoc improvements; Joining singularization methods
#207 Applying IntelliJ formatting style
#207 Formatting
#229 Add null-check before auto-unboxing in direct assignments
#14 Add basic support for @AfterMapping / @BeforeMapping methods
#14 support @TargetType in @AfterMapping/@BeforeMapping methods
Fix error message for subsequent tests that fail with compile errors
#14 some improvements as hinted in code review by Sjaak, added / extended some test cases