I just found multichain today and have done a little Googling and don't think that I've found an answer yet. I've seen on other distributed ledgers that there are ways you can send data or messages along with a transaction, and use the protocol as a means of sending a "notarized" message to someone. Is this possible with multichain? If so, how? I came across another product of multichain's, coinspark: http://coinspark.org/ but don't see how multichain and coinspark integrate, if it does, are there any "Getting Started" docs that talk about how to use a newly created multichain blockchain with coinspark to send messages in transactions?. Or is coinspark something that doesn't work with multichain? Thanks.