Prototype ctrl-c-catching behavior.  Surprisingly easy integration with the existing feature from unittest.
Refactored the runner.GreenTestRunner class with a monstrous __init__ into the runner.run() function with only three arguments.
Added a test for regression: '-s 0' would cause a crash.
Silly me.  Restore the cwd AFTER we run the test.
Added a --catch option.
The extra code for conditionally handling catch was bothering me, especially since I couldn't see why you wouldn't want it enabled.  So I removed all of the conditional code and just always enable it.
Bumped to 1.5.0.  Fixes #5.