Send initiateMmtMultisigTest when loading a wallet

[nikolai-b]

Along with #5 it would be good to offer to send an initiateMmtMultisigTest message when a wallet is loaded that hasn't go an initiateMmtMultisigTest message already.

[ameba23]

this one is driving me crazy. much like the problem with the transactions, i cant find a way to uniquely identify the wallet. getMpk gives a different master public key for each cosigner. the electrum gui will give us master public keys of all cosigners which is what we need here.

we could use listAddresses to find some matching addresses. i have the feeling this is unreliable but its the best i can come up with right now. the txid of the wallet's oldest transaction? only works when there is already a transaction so not much use.

[ameba23]

publishing these init messages is now implemented.

as a work-around the wallet is identified by finding our mpk, but this is not great because we can only verify our own mpk not that of our cosigners, and in principle its possible to use this for more than one wallet (not a unique identifier). Once we are not relying on electrum i would suggest using the hash of concatonating all cosigners mpks together.

currently using:

function identifyWallet(allWallets, mpk) {
  return Object.keys(allWallets).find(function(aWallet) {
    return Object.keys(allWallets[aWallet].xpub).indexOf(mpk) > -1;
  });
}