把渲染器作为依赖Scene的组件，方便在编辑器中编辑。

[wardenfeng]

View.render 中\n \n //绘制阴影图\n shadowRenderer.draw(this.gl, this.scene, this.camera);\n skyboxRenderer.draw(this.gl, this.scene, this.camera);\n // 默认渲染\n forwardRenderer.draw(this.gl, this.scene, this.camera);\n outlineRenderer.draw(this.gl, this.scene, this.camera);\n wireframeRenderer.draw(this.gl, this.scene, this.camera);\n\n---\n迁移自 Gitee Issue #I19D2D\n原链接: https://gitee.com/feng3d/feng3d/issues/I19D2D