Small fixes and simplification
Cool, will take a look
 The two test failures are relted to non-deterministic ordering.. I need to work up a real fix for those.

I cherry-picked 9c12013f48d447584584781114f59a8fc7ca126f however, which was your fixes to the test runner.  Thanks a ton!

I've removed some not used imports, changed test runner a little bit (so it can actually run single test, i.e.:

```
./runtest.py QueryTests.test_count
```

Fixed 2 (out of 3) failing tests. Last one (_QueryTests.test_count_) ... well, tried to debug it but the problem seem to be somewhere during iteration of _SelectQuery(Blog)_, not sure where exactly.
