Added missing OSG_EXPORT to fix Windows build
Added missing OSG_EXPORT to fix Windows build

git-svn-id: aa838dfc23441284dd616281de4245daec5d2135@15131 16af8721-9629-0410-8352-f15c8da7e697

omega-hub/osg,omega-hub/osg,omega-hub/osg,omega-hub/osg