Add support for system event handlers. This is used by memoryLogger
to ensure it is executed before other loggers. Also fixing some
issues in phantomjs.
Add support for suite level test ignoring.
Add support for simple spying on a function (similar to mocks).
Add support for mock time. The setTimeout/setInterval functions
are replaced by calling test.mockTime()/test.restoreTime(). The
time can then be incremented by calling test.tick(ms).