Sandboxes can open windows.

The open window will inherit the sandbox restrictions.
You need to set `sandbox.popups` to true when creating the sandbox.

Firefox doesn't currently support the HTML5 feature `allow-popups`.
See https://bugzilla.mozilla.org/show_bug.cgi?id=766282

```js
  var sandbox = Oasis.createSandbox({
    url: 'http://example.com/profile_viewer.html',
    capabilities: [ 'account' ],
    sandbox: {
      popups: true
    }
  });
```

[Fixes #4]
Sandboxes can submit forms.

You need to set `sandbox.forms` to true when creating the
sandbox.

This relies on the HTML5 `allow-forms`.

```js
  var sandbox = Oasis.createSandbox({
    url: 'http://example.com/profile_viewer.html',
    capabilities: [ 'account' ],
    sandbox: {
      forms: true
    }
  });
```

[Fixes #4]