example bug fix, cleanup cont., QTKit video plugin, AVFoundation video plugins

- deleted legacy video/tracker plugins
- moved new plugins to osgARTPlugins (osg distribution style)
- deleted old examples
 -removed etc/cmake for CMakeModules directory (osg distribution style)
- added new alpha QTKit video plugin (only support RGB out so far)
- added new alpha AVFoundation video plugin (only support RGB out so
far)
-