MongoCursor::key() should return _id
fix rewind
Merge branch 'master' of github.com:koubas/mongofill into CountAndfetchDocuments

* 'master' of github.com:koubas/mongofill:
  MongoRegex
  MongoCollection::count() should return an int
  MongoCollection::remove()
fix test
Merge pull request #13 from mcuadros/CountAndfetchDocuments

MongoCursor::count() and better fetch policy