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)

src/osgAnimation/RigGeometry.cpp

@@ -24,7 +24,7 @@ osg::BoundingBox RigComputeBoundingBoxCallback::computeBound(const osg::Drawable
 {
     const osgAnimation::RigGeometry& rig = dynamic_cast<const osgAnimation::RigGeometry&>(drawable);
 
-    // if a valid inital bounding box is set we use it without asking more
+    // if a valid initial bounding box is set we use it without asking more
     if (rig.getInitialBound().valid())
         return rig.getInitialBound();