Refactor RPC submit and submit_json.
Refactor RPC submit and submit_json.

ripple/ripple-lib,darkdarkdragon/ripple-lib,wilsonianb/ripple-lib,ripple/ripple-lib,darkdarkdragon/ripple-lib,wilsonianb/ripple-lib,ripple/ripple-lib,ripple/ripple-lib,wilsonianb/ripple-lib,darkdarkdragon/ripple-lib