* Electron version: 1.6.0, does _not_ repro in 1.4.x
* Operating system: Win32 tested, others possible

It appears that even if you create a window with `focusable: false` and `show: false`, calling `loadURL` on it will cause it to accept window focus and for other windows to lose focus.

### How to reproduce

Open the default Electron app

```js
BW = require('electron').remote.BrowserWindow
let ourWindow = BW.getFocusedWindow()
ourWindow.on('blur', () => console.log("Lost it!"))

hidden = new BW({show: false, width: 500, height: 500, focusable: false})
hidden.loadURL("http://www.yahoo.com")

>>> "Lost it!"
```

This breaks anyone using background windows for computation such as VS Code and Slack (via electron-remote), because whenever a background task kicks off, users can't type anymore
atom/browser/native_window_views.cc
#if defined(OS_WIN)
  FlipWindowStyle(GetAcceleratedWidget(), maximizable, WS_MAXIMIZEBOX);
#endif
  maximizable_ = maximizable;
}
bool NativeWindowViews::IsMaximizable() {
#if defined(OS_WIN)
  return ::GetWindowLong(GetAcceleratedWidget(), GWL_STYLE) & WS_MAXIMIZEBOX;
#else
  return true;  
#endif
}
void NativeWindowViews::SetFullScreenable(bool fullscreenable) {
  fullscreenable_ = fullscreenable;
}
bool NativeWindowViews::IsFullScreenable() {
  return fullscreenable_;
}
void NativeWindowViews::SetClosable(bool closable) {
#if defined(OS_WIN)
  HMENU menu = GetSystemMenu(GetAcceleratedWidget(), false);
  if (closable) {
    EnableMenuItem(menu, SC_CLOSE, MF_BYCOMMAND | MF_ENABLED);
  } else {
    EnableMenuItem(menu, SC_CLOSE, MF_BYCOMMAND | MF_DISABLED | MF_GRAYED);
  }
#endif
}
bool NativeWindowViews::IsClosable() {