message: add function to find out is a BlockDate is a genesis date
diff: @@ -96,6 +96,13 @@ impl BlockDate {
  &BlockDate::Normal(ref s) => BlockDate::Normal(s.next()),
  }
  }
  +
  + pub fn is_genesis(&self) -> bool {
  + match self {
  + BlockDate::Genesis(_) => true,
  + _ => false
  + }
  + }
  }
  impl fmt::Display for BlockDate {
  