Closes #1210 Quaternion.lookAt now has a return value (#1223)

jme3-core/src/main/java/com/jme3/math/Quaternion.java

@@ -1371,13 +1371,14 @@ public final class Quaternion implements Savable, Cloneable, java.io.Serializabl
      *            a vector indicating the local up direction.
      *            (typically {0, 1, 0} in jME.)
      */
-    public void lookAt(Vector3f direction, Vector3f up) {
+    public Quaternion lookAt(Vector3f direction, Vector3f up) {
         TempVars vars = TempVars.get();
         vars.vect3.set(direction).normalizeLocal();
         vars.vect1.set(up).crossLocal(direction).normalizeLocal();
         vars.vect2.set(direction).crossLocal(vars.vect1).normalizeLocal();
         fromAxes(vars.vect1, vars.vect2, vars.vect3);
         vars.release();
+        return this;
     }
 
     public void write(JmeExporter e) throws IOException {