libgdx runtime, box2d as extension

Need new lib in build path to run box2d test.

spine-libgdx/.classpath

@@ -5,5 +5,7 @@
 	<classpathentry kind="src" path="test"/>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.6"/>
 	<classpathentry combineaccessrules="false" exported="true" kind="src" path="/gdx-backend-lwjgl"/>
+	<classpathentry combineaccessrules="false" exported="true" kind="src" path="/gdx-box2d"/>
+	<classpathentry kind="lib" path="/gdx-box2d/libs/gdx-box2d-natives.jar"/>
 	<classpathentry kind="output" path="bin"/>
 </classpath>