Edicy/wysihtml5 — pull request #89 by Waxolunist (2014-10-03 15:20:59+00:00)
Title: Test for undefined in focus method

In current Chromium the focus method gets sometimes called with this set to window. Thus an exception is thrown, which is disturbing during debugging.

```
Uncaught TypeError: Cannot read property 'ownerDocument' of undefined
```

This PR tests for undefined.