Disable stencil buffer by default

src/renderers/WebGLRenderTarget.js

@@ -36,7 +36,7 @@ function WebGLRenderTarget( width, height, options ) {
 	this.texture.minFilter = options.minFilter !== undefined ? options.minFilter : LinearFilter;
 
 	this.depthBuffer = options.depthBuffer !== undefined ? options.depthBuffer : true;
-	this.stencilBuffer = options.stencilBuffer !== undefined ? options.stencilBuffer : true;
+	this.stencilBuffer = options.stencilBuffer !== undefined ? options.stencilBuffer : false;
 	this.depthTexture = options.depthTexture !== undefined ? options.depthTexture : null;
 
 }