Migrate to `python-bitcoinlib` for transaction identification

[adamkrellenstein]

In bitcoin.get_tx_info(), after a particular block, use library to do tx parsing.

[petertodd]

FWIW I just pushed a relatively major change to python-bitcoinlib to switch to making the datastructures immutable by default, so if you start using it make sure you're using the latest version. I'll be releasing v0.2 with those changes soon.

[adamkrellenstein]

Going to use python-bitcoinlib just for iterating through the inputs and outputs, and for returning the scriptSig scriptPubKey (I was tired last night); will do the parsing from scratch.

[petertodd]

What do you mean by "will do the parsing from scratch"?

[adamkrellenstein]

I mean checking that the script is of a certain form and extracting the pubkey/pubkeyhash, for strictness, stability and transparency.

[petertodd]

Right, at the binary bytes level?

I'd stick with using python-bitcoinlib for that too - it's all 100% consensus critical anyway.

[adamkrellenstein]

At the OP code level... So I want to leave, e.g. get_checksig() and get_checkmultisig().

[petertodd]

Ok, that sounds fine to me.

[adamkrellenstein]

This is done in the multisig branch.

[petertodd]

Took a quick look through the code, looks reasonable.

In your 'requirements' doc you probably want to change '0.2' to the full '0.2.1'

[adamkrellenstein]

Great---thanks!

[adamkrellenstein]

Now in PR #298.