[c-lightning] Core-Lightning Release v0.12.0 [Web 8-init]

[lisa neigut]

We're pleased to announce the 0.12.0 release of core-lightning, named by
@adi2011.

**Developers**: please note the Great Msat Migration in the APIs!

## Highlights for Users

- *NEW* Built-in `bookkeeper` plugin! This plugin tracks all movements of
msats for your node, gives you a better idea of your costs and revenues,
prints out CSVs that are uploadable to Koinly and CoinTracker, lets you
inspect the on-chain footprint of a channel (useful when it goes to chain).
Check out the new `bkpr-` prefixed commands.
- *NEW* Built-in `commando` plugin! This lets you create runes to allow
access to your node from a commando client, which will let you send and
receive RPC commands over the lightning network.
- *NEW* Emergency channel backup ("static backup")! Keep track of what
peers you have channels with, and in case of node failure ask those peers
to close the channel.
- *NEW* zeroconf channels are possible for whitelisted peers.
- `hsmtool` has a new command, `checkhsm`, which will let you check a BIP30
passphrase against the `hsm_secret`.
- Multiple `log-file` options will open multiple files for logging.
- Various crashes and issues fixed in `connectd` including crash on peer
reconnect and large memory usage when many concurrent peers.
- PSBT: fixes signature encoding to comply with BIP-0174.
- We added dynamically detected public IP addresses to `getinfo`.
- Due to dependency issues on some platforms, a tarball of pre-generated
manual pages is included with this release.


## Highlights for the Network

- We prefer IPv6 connections when available.
- We now accept spam gossip and use it for routing, but don't relay it.
- We no longer create gossip messages with zlib encoding (but still
understand them).
- We treat LND "internal error" as warnings, not force close events
(reverts to v0.10.0 behavior).


## Highlights for Developers

- `_msat` fields are added wherever they were missing in the API: they're
still currently an "msat"-suffixed string, but will soon bean integer
value. Test with deprecated_apis=false.
- The `channel_state_changed` notification now fires when a channel moves
into state `CHANNELD_AWAITING_LOCKIN`.
- `htlc_accepted_hook` will now expose the `short_channel_id` and the
per-channel HTLC `id`.
- `pyln-testing` now includes utilities to read and parse the gossip\_store.
- `startup_regtest.sh` script now includes a `fund_ln` method.
- Rust binaries such as `cln-grpc` now included in our reproducible builds.
- Updated the bolts implementation for pyln-spec.
- Plugins no longer hang indefinitely if `lightningd` closes their
connection.
- M1 architecture support.
- Upgrade docker base image from Debian buster to bullseye, works with
glibc 2.29+.
- Docker images now built with rust plugin `cln-grpc`.


Since v0.11.1 we've had 508 commits from 31 different contributors over 80
days.

A special thanks goes to 9 first time contributors:

- Aditya Sharma
- Alex Myers
- Igor Bubelov
- Justin Moon
- Peter Neuroth
- Swapnil
- Jose A.P.
- Brian Barto
- AutonomoousOrganization


~ @niftynei, Christian, and Rusty