Return the texture while Spine is using it.

spine-cocos2dx/src/spine/spine-cocos2dx.cpp

@@ -35,12 +35,14 @@ USING_NS_CC;
 
 void _spAtlasPage_createTexture (spAtlasPage* self, const char* path) {
 	Texture2D* texture = Director::getInstance()->getTextureCache()->addImage(path);
+	texture->retain();
 	self->rendererObject = texture;
 	self->width = texture->getPixelsWide();
 	self->height = texture->getPixelsHigh();
 }
 
 void _spAtlasPage_disposeTexture (spAtlasPage* self) {
+	((Texture2D*)self->rendererObject)->release();
 }
 
 char* _spUtil_readFile (const char* path, int* length) {