Ready: Riak CS Multibag docs

- [x] Command line docs in **Riak CS Command Line Tools**
- [x] Configuration in `app.config`
- [x] Architectural description
- [x] Stanchion configuration
- [x] Etc.
Is it better to add a fact that weights are stored in the master bag and are shared with every riak cs nodes?

As a result, an operator can set weights at one of CS nodes and need not repeat to do so at other CS ndoes.