Added support to StateAttribute/State to support PROTECTED flag for modes and attributes

so that they cannot be overriden from above via the OVERRIDE flag.  This is
useful for things like manipulators that have handles display in the scene, you
might want to prevent their state being affected by other overriding of
light, wireframe modes etc.

include/osg/StateAttribute

@@ -78,14 +78,18 @@ class SG_EXPORT StateAttribute : public Object
             OFF          = 0x0,
             /** means that associated GLMode is enabled and Override is disabled.*/
             ON           = 0x1,
-            /** Overriding of GLMode's or StateAttributes is enabled.*/
+            /** Overriding of GLMode's or StateAttributes is enabled, so that state below it is overriden.*/
             OVERRIDE     = 0x2,
+            /** Protecting of GLMode's os StateAttributes is enabled, so that state from above connot override this and below state.*/
+            PROTECTED    = 0x4,            
+#ifdef USE_DEPRECATED_API            
             /** Equivilant to OFF | OVERRIDE.*/
             OVERRIDE_OFF = 0x2,
             /** Equivilant to ON | OVERRIDE.*/
             OVERRIDE_ON  = 0x3,
+#endif            
             /** means that GLMode or StateAttribute should in inherited from above.*/
-            INHERIT      = 0x4
+            INHERIT      = 0x8
         };
         
         /** Type identifier to differentiate between different state types. */