Prevents NaN time when animation length is 0 (case of a pose)

jme3-core/src/main/java/com/jme3/animation/AnimationUtils.java

@@ -31,10 +31,6 @@
  */
 package com.jme3.animation;
 
-import static com.jme3.animation.LoopMode.Cycle;
-import static com.jme3.animation.LoopMode.DontLoop;
-import static com.jme3.animation.LoopMode.Loop;
-
 /**
  *
  * @author Nehon
@@ -52,7 +48,7 @@ public class AnimationUtils {
      * @return 
      */
      public static float clampWrapTime(float time, float duration, LoopMode loopMode){
-        if (time == 0) {
+         if (time == 0 || duration == 0) {
             return 0; // prevent division by 0 errors
         }        
         switch (loopMode) {