Updates osgAnimation

This updates is mainly for the gles plugint to work correctly.

* adds Quaternion array
* reintroduces `KeyframeContainer::linearInterpolationDeduplicate`
* fixes MorphGeometry OSG serialization (target names)

include/osgAnimation/Animation

@@ -70,6 +70,7 @@ namespace osgAnimation
          */
         void computeDuration();
         double getDuration() const;
+        double computeDurationFromChannels() const;
 
         void setWeight (float weight);
         float getWeight() const;
@@ -87,8 +88,6 @@ namespace osgAnimation
 
         ~Animation() {}
 
-        double computeDurationFromChannels() const;
-
         double _duration;
         double _originalDuration;
         float _weight;