adds option arg (for crossOrigin attribute) to loadImage (Automattic#1402)

* adds crossOrigin attribute to loadImage

without that using the image later with webgl errors
 DOMException: Failed to execute 'texImage2D' on 'WebGLRenderingContext': The image element contains cross-origin data, and may not be loaded.

* Standard Style

* support any properties on an HTMLImageElement

Automattic#1402 (comment)

* loadImage accepts any options now

Author: thisconnect

browser.js

@@ -18,9 +18,9 @@ exports.createImageData = function (array, width, height) {
   }
 }
 
-exports.loadImage = function (src) {
+exports.loadImage = function (src, options) {
   return new Promise((resolve, reject) => {
-    const image = document.createElement('img')
+    const image = Object.assign(document.createElement('img'), options)
 
     function cleanup () {
       image.onload = null

types/index.d.ts

@@ -294,7 +294,7 @@ export function createImageData(width: number, height: number): ImageData
  * @param src URL, `data: ` URI or (Node.js only) a local file path or Buffer
  * instance.
  */
-export function loadImage(src: string|Buffer): Promise<Image>
+export function loadImage(src: string|Buffer, options?: any): Promise<Image>
 
 /**
  * Registers a font that is not installed as a system font. This must be used