Add memo field binary types.
Add memo field binary types.

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