mode by using a _texParamtersDirty flag in combination with an
applyTexParamters(State&) method which does the paramters setting in one
tidy bundle. This new implementations replaces the CompileFlags submitted
yesterday.
Simplified NodeCallback by remove osg::NodeCallback::Requirements as they
are no longer needed.
Fixed comments in Drawable.
Put guards around cosf definations so that they are only used under Win32/Mac.
Fixed warning in CullVisitor.