Class D transaction type

[LOLLOLOOLOL]

Class D transactions include the reference public key and the public key of the Exodus address in a multisig output. A third public key in the multisig output may included embedded Master Protocol data.

The goal of the Class D transaction is to optimize Class B transactions by reducing size, cost, chance that multisig outputs will remain unspent, and in some cases, increase the amount of bytes available to embed MP data without increasing cost (over Class B transactions, that is).

Relevant: Find a clever trick to lower the cost of transactions, #192

[LOLLOLOOLOL]

This also sets the stage for a very elegant method of implementing a Multi Send transaction type - for which I'll create a pull request if Class D transactions are merged into the spec.

The idea is that a Class D transaction only requires a single output for a Simple Send transaction type. By including multiple Class D encoded Simple Send packets in a transaction we create the Multi Send transaction type, and reduce the overhead of the Simple Send.

See here: https://github.com/LOLLOLOOLOL/spec/tree/multiSend

[LOLLOLOOLOL]

Related issue #237 that proposes a transition away from the notion that Master Protocol coins are sent to and received from Bitcoin addresses.

[dexX7]

Hi,

in an attempt to clean up the current specification, I'm going to close old and outstanding pull requests. Please note, it's tagged as "old idea", so the work is not wasted and we can potentially review it at some point later.

Please feel free to resubmit it as new pull request, if you still think it's a good idea.