JS: Add temporary support for RPC tx.
JS: Add temporary support for RPC tx.

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