WS: Add support for ledger_entry to return an account_root.
WS: Add support for ledger_entry to return an account_root.

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