I do a lot of HTML generation just with JavaScript and am finding myself creating `index.html` files that have code that looks like this:

     <!DOCTYPE html><html><head><script src="index.js"></script></head><body></body></html>

It would be nice to be able to do:

     browserWindow.loadHTML('<!DOCTYPE html><html><head><script src="index.js"></script></head><body></body></html>');

It would be even more awesome to do:

     browserWindow.loadScript(pathToScript);

I tried to use the `preload` option for `BrowserWindow` and using `loadURL('about:blank')`, but this has an unintended side effect of not allowing you to reference other script or CSS files using relative paths.

What do you think about proposed feature?
atom/browser/api/atom_api_web_contents.cc
int opener_render_process_id,
                                     int opener_render_frame_id,
                                     const std::string& frame_name,
                                     const GURL& target_url,
                                     content::WebContents* new_contents) {
  v8::Locker locker(isolate());
  v8::HandleScope handle_scope(isolate());
  auto api_web_contents = CreateFrom(isolate(), new_contents, BROWSER_WINDOW);
  Emit("-web-contents-created", api_web_contents, target_url, frame_name);
}
void WebContents::AddNewContents(content::WebContents* source,
                                 content::WebContents* new_contents,
                                 WindowOpenDisposition disposition,
                                 const gfx::Rect& initial_rect,
                                 bool user_gesture,
                                 bool* was_blocked) {
  v8::Locker locker(isolate());
  v8::HandleScope handle_scope(isolate());
  auto api_web_contents = CreateFrom(isolate(), new_contents);
  if (Emit("-add-new-contents", api_web_contents, disposition, user_gesture,
      initial_rect.x(), initial_rect.y(), initial_rect.width(),
      initial_rect.height())) {
    api_web_contents->DestroyWebContents();
  }
}
content::WebContents* WebContents::OpenURLFromTab(