message: implement an hexadecimal debug for HDAddressPayload
diff: @@ -6,11 +6,13 @@ use self::rcw::hmac::{Hmac};
  use self::rcw::sha2::{Sha512};
  use self::rcw::pbkdf2::{pbkdf2};
  -use std::{iter::repeat, ops::{Deref}};
  +use std::{iter::repeat, ops::{Deref}, fmt};
  use hdwallet::{XPub};
  use raw_cbor::{self, de::RawCbor, se::{self, Serializer}};
  +use util::hex;
  +
  const NONCE : &'static [u8] = b"serokellfore";
  const SALT : &'static [u8] = b"address-hashing";
  const TAG_LEN : usize = 16;
  @@ -113,7 +115,7 @@ impl HDKey {
  }
  }
  -#[derive(Debug, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord, Clone)]
  +#[derive(Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord, Clone)]
  pub struct HDAddressPayload(Vec<u8>);
  impl AsRef<[u8]> for HDAddressPayload {
  fn as_ref(&self) -> &[u8] { self.0.as_ref() }
  @@ -140,6 +142,11 @@ impl Deref for HDAddressPayload {
  type Target = [u8];
  fn deref(&self) -> &Self::Target { self.0.as_ref() }
  }
  +impl fmt::Debug for HDAddressPayload {
  + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  + write!(f, "{}", hex::encode(self.as_ref()))
  + }
  +}
  #[cfg(test)]
  mod tests {
  