implementation of GraoicsWindowCocoa:
Enhancements/Bugfixes:
+ now it's possible to integrate osgViewer better into existing
cocoa-applications:
* create one or more NSOpenGLView(s) and add these to your window(s)
* create one or more NSWindows
* disable the integrated event-polling of osgViewer, and let the work be
done by Cocoa / NSApplicationRun. You'll have to run the osgViewer's
runloop in a separate thread
+ missing menu-event-handling implemented
+ added NSAutoReleasePools where necessary, this fixes some memory-leaks
+ fixed some crashes and thread-issues"
