From John Kelso, add support for default frame time for children of a Sequence node

include/osg/Sequence

@@ -44,6 +44,12 @@ public :
     /** Get time for child. */
     float getTime(int frame) const;
 
+    /** Set default time in seconds for new child. */
+    void setDefaultTime(float t) {_defaultTime = t;}
+
+    /** Get default time in seconds for new child. */
+    float getDefaultTime(void) const {return _defaultTime;};
+
     /** Get number of frames */
     inline unsigned int getNumFrames() const { return _frameTime.size(); }
 
@@ -107,6 +113,8 @@ protected :
     float _speed;
     int _nreps, _nrepsremain;
 
+    float _defaultTime ;
+
     SequenceMode _mode;
 };