Merge pull request #402 from arstrube/filters-1

Multiple -sg and -sn Commandline Parameters - Step 1
Merge pull request #403 from arstrube/filters-2

Multiple -sg and -sn Commandline Parameters - Step 2
Remove pointless getters; properly name setters
Implement changes in CommandLineArguments
Implement CommandLineTestRunner

Also remove temporary workarounds from CommandLineArguments
Partially implement TestRegistry
Add remaining changes

Behavior is as before; e.g. if both a single group name and
a single test name is given, both must match.