From Brede Johansen, tweaks to emitter classes to make them more extensible.

include/osgParticle/Emitter

@@ -65,7 +65,6 @@ namespace osgParticle
         
         virtual void emit(double dt) = 0;
         
-    private:        
         bool usedeftemp_;
         Particle ptemp_;
     };

include/osgParticle/ModularEmitter

@@ -79,7 +79,7 @@ namespace osgParticle
         virtual ~ModularEmitter() {}
         ModularEmitter &operator=(const ModularEmitter &) { return *this; }
         
-        void emit(double dt);
+        virtual void emit(double dt);
         
     private:
         osg::ref_ptr<Counter> counter_;