Final candidate 0.8.7 changes

[Sjors]

I'm pretty close to getting 0.8.6 to work with libwally-swift. I'll let you know if I run into any issues that might be nice for 0.8.7

(done)

[jgriffiths]

(done)

Thanks @Sjors - 0.8.7 is coming very shortly and has some map function helpers which should allow you to wrap map functions more nicely (for example, in python we can convert to and from python dicts and maps trvially now).

0.8.8 will also be out pretty quickly after that, and will include updates to the signing interface to allow bespoke signing without having to re-implement all of the logic in the current psbt_sign call. As an example, you'll be able to sign individual inputs, and sign directly using a bip32 hdkey without having to find and derive matching private keys yourself.

[jgriffiths]

@k-matsuzawa @ko-matsu I'd be interested in your feedback on the new WASM-based JS/Typescript wrapper.

The intention is to replace the existing wrappers with the new ones, since the new ones cover the entire wally API now, and are auto-generated instead of having to be manually updated. I expect to remove the old wrappers in release 0.8.8, please let me know if you are able to switch over and/or whether this will cause any issues for you, thanks.

[k-matsuzawa]

@jgriffiths Thanks! This is so good! I will switch to the new JS/Typescript wrapper.

[LeoComandini]

ACK d868fb1c898dbf746ca69bea89e11c9699208edd, code review, haven't reviewed the js changes, tested locally, did a couple of smoke tests.