v0.8.1: Channel to the Moon

We're pleased to announce 0.8.1, named by @vasild (who last release was a new committer!) Despite the holiday break and Rusty's month off, commit numbers are only down 20%! ## Highlights for Users - We now support gifting msat to the peer when opening a channel, via `push_msat`, providing a brand new way to lose money! - Invoice routehints can be overridden using `exposeprivatechannels`: try setting to `[]` to eliminate all of them to fit your invoice in twitter messages! - Wallet `withdraw` transactions now set nLocktime, making them blend in more with other wallets. - Preliminary support for plugins hooks which can replace the default `bitcoin-cli` with other blockchain querying methods (API may change in future releases though!). - `listforwards` now records the outgoing short_channel_id, even if it wasn't possible to start forwarding. ## Highlights for the Network - Plugins can set additional feature bits, for more experimentation. - More than one plugin can register for the `htlc_accepted` hook: others will become multi-user in future releases. - Documentation updates, which had lagged recent changes. - Prevent a case where grossly unbalanced channels could become unusable. More details can be found in https://github.com/ElementsProject/lightning/blob/v0.8.1/CHANGELOG.md Thanks to everyone for their contributions and bug reports; please keep them coming! Since 0.8.0 we've had 257 commits from 17 different authors, with 5 first-time contributors! - Niklas Claesson @NickeZ - @minidisk1147 - Ken Sedgwick @ksedgwic - Zoe Faltibà @zoedberg - Glen Cooper @GlenCooper Cheers, Rusty, Lisa, Christian, and ZmnSCPxj.