Use mongodb-native 1.3.x

Change-Id: I18fe3f72fa92dec7cda4776fe1977c9b4ea28f09
Work with mongodb-native 1.3.x

Change-Id: I0558e737cba510e3ae774eec08a36ceffa4bed84
Removed callback from open_db

Change-Id: Ifae97bfd98c1c46b7610f75e00899a552392161b