Separate the crate into several crates

[Kixunil]

It'd be beneficial for people to not have to download and compile whole crate if they only need to work with part (e.g. transactions).

I'm willing to help with that.

[apoelstra]

I think this is a reasonable thing to do, though I'm not sure how best to separate things. My uses tend to use pretty-much the whole crate except for the network/p2p stuff. Can you make a PR?

[Kixunil]

OK, do you want to have them in the same repository, just separate crate?

My thinking for now: Things that may be reasonable to use without the blockchain/txses (addresses, base58, coin amount - not a separate type now but it may be good idea to create one), transaction-related data, blocks, network.

[apoelstra]

Yes, same repo, just different crates.

From the network crate, the Network enum is constantly useful (for distinguishing between testnet and mainnet) and is used frequently with the address structures. In turn the address structures heavily depend on the script de/serialization, which depends both on transaction-related data and on the consensus serializer (which is also in the network module IIRC).

[Kixunil]

OK, I'll look at it during the weekend.

BTW any plans to add support for SegWit addresses? As far as I see it isn't there yet.

[apoelstra]

Yes, I plan to add bech32 support after Core does, both so I can be sure everything is finalized, and because it will give me an easy way to generate a ton of test vectors :)

[apoelstra]

I'm going to close this because it doesn't have any clear success condition. We have plans for some specific modules (contracthash stuff, anyway) to be pulled out of rust-bitcoin.