Fixed issue with DO tick events having no target.

Signed-off-by: Grant Skinner <info@gskinner.com>
Added tick event propagation perf test.

Signed-off-by: Grant Skinner <info@gskinner.com>
Simplified the addRemoveChild perf test.

Signed-off-by: Grant Skinner <info@gskinner.com>
Removed TODO from EventDispatcher.

Tested, and didn't see a significant perf benefit.

Signed-off-by: Grant Skinner <info@gskinner.com>
Improved performance & handling of custom data in tick()

Event object is now shared for all dispatchers. Custom data is now on a single props object param on update/tick.

Signed-off-by: Grant Skinner <info@gskinner.com>