Improved test coverage
Tests for ServiceFactory
Improved domain.Exercise tests based on PIT reports
Merged master to MoreTests
More tests, refactored Fetchers to use DependecyInjection
Updated services.Courses tests
Refactored WebDAO to use Dependecy Injection
Added tests to CourseList, ExerciseList and UrlExtension
Merged MoreTests to Master
Removed unreachable code from ExerciseKey