Added removeValuesAt(int[] rows) method to the ProblemModel class
Added removeProblems(Collection problems) method to the ProblemCatalog class
Modified the ProblemCatalogs removeProblem(Problem problem) method to return
a boolean
Modified Files:
src/java/de/fhworms/ztt/ox/examrepository/ProblemCatalog.java
src/java/de/fhworms/ztt/ox/examrepository/ProblemModel.java
src_test/java/unit/de/fhworms/ztt/ox/examrepository/ProblemCatalogTest.java
src_test/java/unit/de/fhworms/ztt/ox/examrepository/ProblemModelTest.java
