local function pointer to avoid compiler warnings related to case void*.
Moved various OSG classes across to using setGLExtensions instead of getGLExtensions,
and changed them to use typedef declarations in the headers rather than casts in
the .cpp.
Updated wrappers
Note, this required adding a unsigned int context ID to the osg::isGLUExtensionSupported(,)
and osg::isGLExtensionSupported(,) functions. This may require reimplementation
of end user code to accomodate the new calling convention.
extra pass to doing tri stripping in the osgUtil::Optimzer.
Added validity checks into osg::TexEnvCombine to catch eronous enumarant values.
Improved the efficient of CullingSet's handling of new transforms.
Added a copy shared subgraphs and subdivision code into osgUtil::Optimizer.
