Unified the setup of version numbers so that they all are based on the version

number setup in the include/osg/Version header file.

src/osgDB/Version.cpp

@@ -11,10 +11,13 @@
  * OpenSceneGraph Public License for more details.
 */
 #include <osgDB/Version>
+#include <osg/Version>
+
+extern "C" {
 
 const char* osgDBGetVersion()
 {
-    return "1.9";
+    return osgGetVersion();
 }
 
 
@@ -22,3 +25,5 @@ const char* osgDBGetLibraryName()
 {
     return "OpenSceneGraph DB (data base) Library";
 }
+
+}