Determine what, if any, existing device event logic should be 'disabled' in PsychoPy when ioHub is being used.

[isolver]

For example, it seems like it would be totally redundant to still have pyglet message handlers for keyboard and mouse events for the window when ioHub was providing these events. Should be easy to just have a flag that either registers or does not register the appropriate event handlers??

Initially during testing and debugging, it will be 'good' to have both event streams running; as the two can be compared and it may be a source of data that could help fix ioHub issues found in terms of key mapping / unicode encoding etc.