fixed two problems with asset manager:

1. can't load classes from asset class loaders.
2. can't load resources from asset class loaders.

jme3-core/src/main/java/com/jme3/export/SavableClassUtil.java

@@ -34,6 +34,7 @@ package com.jme3.export;
 import com.jme3.animation.Animation;
 import com.jme3.effect.shapes.*;
 import com.jme3.material.MatParamTexture;
+
 import java.io.IOException;
 import java.lang.reflect.Field;
 import java.util.ArrayList;
@@ -189,14 +190,19 @@ public class SavableClassUtil {
         }
 
         String newClassName = remapClass(className);
-        synchronized(loaders) {
-            for (ClassLoader classLoader : loaders){
+        synchronized (loaders) {
+            for (ClassLoader classLoader : loaders) {
+                final Class<?> loadedClass;
+                try {
+                    loadedClass = classLoader.loadClass(newClassName);
+                } catch (final ClassNotFoundException e) {
+                    continue;
+                }
                 try {
-                    return (Savable) classLoader.loadClass(newClassName).newInstance();
+                    return (Savable) loadedClass.newInstance();
                 } catch (InstantiationException e) {
                 } catch (IllegalAccessException e) {
                 }
-
             }
         }
 

jme3-core/src/plugins/java/com/jme3/asset/plugins/ClasspathLocator.java

@@ -37,6 +37,7 @@ import java.io.File;
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.util.List;
 import java.util.logging.Logger;
 
 /**
@@ -90,6 +91,17 @@ public class ClasspathLocator implements AssetLocator {
         }else{
             url = Thread.currentThread().getContextClassLoader().getResource(name);
         }
+
+        if (url == null) {
+            final List<ClassLoader> classLoaders = manager.getClassLoaders();
+            for (final ClassLoader classLoader : classLoaders) {
+                url = classLoader.getResource(name);
+                if(url != null) {
+                    break;
+                }
+            }
+        }
+
         if (url == null)
             return null;