The implementation of this feature (without moveCollections) has the following work items:
- Add new parsing functionality to mongos/mongod for chunk manager logic
- Build new scatterCollections and createCollection commands
- Deprecate enableSharding
- Moderate refactoring of the mongod config reload codebase (d_logic.cpp)
To implement moveCollections some additional work is probably necessary, but we can leverage much of the cloneCollection framework.