serveral fixes and bson object support
MongoCollection::batchSize, and correct limit bahaviors
Merge branch 'master' of github.com:koubas/mongofill

* 'master' of github.com:koubas/mongofill:
  bson fixes for MongoCode
  more fixes in tests
  fixes, tests and coding style
  forgotten changes
  wrong class name and small fixes
  MongoDbRef class, no tests yet