Moved classes from org.bson.types out of bson module and into either driver or driver-compat.  This includes the Document class, which is now in org.mongodb in driver module.  Also dealt with CodeWScope binary compatibility issue by moving it into driver-compat, where it can safely use DBObject, and creating a new class in driver module called CodeWithScope that depends on Document.
Moved JsonWriter from bson module to driver module, since the JSON extended syntax is part of MongoDB, not the BSON spec