Change void* parameter in beginScene to SExposedVideoData&, which will allow to configure more features. Due to the constructor for SExposedVideoData this is mostly transparent, just add this type around the currently used pointer.
Please also note that the OpenGL context handling is not yet working, so no real enhancement so far.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3013 dfc29bdd-3216-0410-991c-e03cc46cb475