Add hints for vtkCocoaRenderWindow methods

The OS X dashboards are getting void_p conversions instead of proper
tuple conversions.

Change-Id: I6b5bd7fb999d0016138471a95ffe7d49621de3da
Merge topic 'add-cocoa-render-window-hints' into master

db11cea5 Add hints for vtkCocoaRenderWindow methods