AttributeError in ViewResults after Search with comma

When using Client.search() with a query-parameter that contains a comma (like q="some, string"), the iterator() method of the returned ViewResults object fails with an AttributeError

```
File "/usr/local/lib/python2.6/site-packages/couchdbkit-0.5.1-py2.6.egg/couchdbkit/client.py", line 825, in iterator
rows = self._result_cache.get('rows', [])

AttributeError: 'list' object has no attribute 'get'
```

I'm using a current checkout of couchdb-lucene and a nearly-current (commit 2f3b58ec5874bf94b35ef21e161812828475fc16 ) checkout of couchdbkit.