Problem removing editor page

```
It is possible to get to a state where an editor page is not removeable.

Traceback (most recent call last):
  File "lib/pynguin/mw.py", line 1657, in removedoc
    doc = documents[docid]
KeyError: 'None'


```

Original issue reported on code.google.com by `miss...@hotmail.com` on 4 May 2014 at 9:05
