COpenGLDriver doesn't seem to need COpenGLCacheHandler or COpenGLTexture as...

COpenGLDriver doesn't seem to need COpenGLCacheHandler or COpenGLTexture as friends. So removed those.
If one of them is needed again please write 'friend class COpenGLCacheHandler' instead of 'friend COpenGLCacheHandler' as 
older gcc compilers (4.4.7) won't accept it otherwise.
Thanks @umen for reporting.


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@5226 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/COpenGLDriver.h

@@ -33,8 +33,6 @@ namespace video
 
 	class COpenGLDriver : public CNullDriver, public IMaterialRendererServices, public COpenGLExtensionHandler
 	{
-		friend COpenGLCacheHandler;
-		friend COpenGLTexture;
 	public:
 		// Information about state of fixed pipeline activity.
 		enum E_OPENGL_FIXED_PIPELINE_STATE