message: add conversion function to retrieve the TxOut of an Output
diff: @@ -105,3 +105,19 @@ pub struct Output {
  /// The desired amount to send to the associated address
  pub amount: Coin
  }
  +impl From<Output> for TxOut {
  + fn from(o: Output) -> Self {
  + TxOut {
  + address: o.address,
  + value: o.amount
  + }
  + }
  +}
  +impl<'a> From<&'a Output> for TxOut {
  + fn from(o: &'a Output) -> Self {
  + TxOut {
  + address: o.address.clone(),
  + value: o.amount
  + }
  + }
  +}
  