Improve client and server entires with unified configuration

[zamotany]

With unified configuration instead of using generators we can write pretty small and trivial babel plugins that will handle generating client entry init files and server entires.

Client

1. Read src/apps.js.
2. Find definition for specific app (passed via options) and store it.
3. Replace everything with static login from string.
4. Append stored app definition.
5. Profit - we can now directly use it (save on disk or use as a virtual module).

Server

1. Read src/apps.js
2. Add wrap values in Document, routes, reducers with require call.
3. Profit - we can now directly use it (save on disk or use as a virtual module).