Add support for bare multisig

[rubensayshi]

code is more or less copy paste of P2SH multisig code with some changes.

also added normalizeSignatures to take existing signatures (as buffer, from a partially signed TX for example) and turn them into TransactionSignature instances, not sure what a good name would be, don't think normalizeSignatures is...

[braydonf]

Would the estimated size include the public keys? Here is an example created with this code: https://test-insight.bitpay.com/tx/dd387bbdeaef66f25b1f1c876df98b1fc6fba62226c01af377800df820bfd338:

<Script: OP_0 72 0x3045022100e633c8ccafde4e3031ea5ced9666336b289f8cf64b6045a879afbd994b824fb502203d16d700e3efd0d957d17941c7b06e7050a9a0132b533742d4e016780d5f1d7001 72 0x30450221008f5dc4a27804b98f00cac764c05b026e49998e7ad469061fd67dc58ecb353acb022012f4b9be8d2a8bf03eed1d01a50c1891d6e691c4f19e9bca7227d8515a4db90901>

And it looks like there are only signatures.

[rubensayshi]

I'll take a look at it and add a test for it and make sure it works properly

[braydonf]

Went through and tested the full process from sending to a multisig output and then signing it, and looks to be working properly.

• out - https://test-insight.bitpay.com/tx/ca0e2b0c285d9db8cb1e9fe9cfe25d534914b4cbb5b8bacd1a45778616bd8b81
• signed - https://test-insight.bitpay.com/tx/dd387bbdeaef66f25b1f1c876df98b1fc6fba62226c01af377800df820bfd338

Looks like there may be some issues regarding the insight-ui display of these inputs/outputs, however unrelated to this PR.

[rubensayshi]

ugh somehow didnt see your comments earlier ...

[rubensayshi]

fixed _estimateSize() and updated test

[braydonf]

LGTM

[matiu]

LGTM

[robby-d]

+1 - counterparty (counterwallet) will make good use of this feature. Looking forward to having it merged.

[rubensayshi]

awesome!

@braydonf will there be a tagged release soon with this?

[braydonf]

Landed in 0.13.10