Allow --group and other flags to be supplied on the commandline and pass them on to the result printer

Currently it's not possible to pass custom flags on the commandline, like the (for us) all-important --group. Also, the debug option is extremely noisy, and you don't really need it unless something's going wrong. If something goes wrong, you can re-run the tests with --debug and pass --seed to set the seed it printed when it went wrong.

This pull request copies some code from the PHPUnit_Extensions_RepeatedTest decorator in order to carry through the options, and it moves the instantiation of the result printer to the runner, where it's located in the PHPUnit original code.