Remove NullTestShell. No more crashes.
No more dropping test cases inserted at _orderedTestHead.
Corrections as per @basvodde
Merge pull request #340 from arstrube/fix_ordered_tests_#2

Fix ordered tests #2 (use NULL)
Removed test that shouldn't be there
Add TestRegistry::getCurrentRepetition()
Add tests to TestRegistryTest.cpp
Fix OrderedTestTest
Make CppUTestExtTests run with -r
Nice.