Added osg::FrameStamp::set/getSimulationTime().

Added setting of osg_SimulationTime and osg_DeltaSimulationTime to the uniforms set by SceneView

Added frame(double simulationTime) and advance(double simulationTime) parameters to
osgViewer::SimpleViewer, Vewer and CompositeViewer.

Updated various examples and Nodes to use SimulationTime where appropriate.

src/osg/AnimationPath.cpp

@@ -230,7 +230,7 @@ void AnimationPathCallback::operator()(Node* node, NodeVisitor* nv)
         nv->getVisitorType()==NodeVisitor::UPDATE_VISITOR && 
         nv->getFrameStamp())
     {
-        double time = nv->getFrameStamp()->getReferenceTime();
+        double time = nv->getFrameStamp()->getSimulationTime();
         _latestTime = time;
 
         if (!_pause)

src/osg/FrameStamp.cpp

@@ -18,6 +18,7 @@ FrameStamp::FrameStamp():Referenced()
 {
     _frameNumber=0;
     _referenceTime=0;
+    _simulationTime=0;
 
     tm_sec=0;            /* Seconds.        [0-60] (1 leap second) */
     tm_min=0;            /* Minutes.        [0-59] */

src/osg/Sequence.cpp

@@ -127,7 +127,7 @@ void Sequence::traverse(NodeVisitor& nv)
         if (framestamp)
         {
     
-            double t = framestamp->getReferenceTime();
+            double t = framestamp->getSimulationTime();
             if (_last == -1.0)
                 _last = t;