modify the file header part of aggsig code

[garyyu]

Gary Yu @garyyu 14:35 Oh, I can’t find file aggsig/main_impl.h in upstream ElementsProject/secp256k1-zkp#23 ? @yeastplume but the first commit message of this file is updating BPs with master and upstream PR 23, what’s exact origin writer of this aggsig/main_impl.h?

Yeastplume @yeastplume 16:18 I wrote the aggsig code based on something andrew did earlier. It doesn't exist anywhere upstream.

Gary Yu @garyyu 16:19 Ok @yeastplume

" I wrote the aggsig code based on something andrew did earlier."

The git commit log lost? I can’t find the andrew’s record.

Yeastplume @yeastplume 16:21 it was in a PR that was withdrawn and it was set up to do multisig while holding a context internally, which didn't really work for us, hence me rewriting it

Gary Yu @garyyu 16:21 Oh, that make sense.

Gary Yu @garyyu 16:23 @yeastplume Could you add yourself into the header?

/**********************************************************************
* Copyright (c) 2017 Andrew Poelstra, Pieter Wuille                  *
* Distributed under the MIT software license, see the accompanying   *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/

It’s awkward I send question to Pieter Wuille about this code, but actually it’s written by you or/and Andrew.

Yeastplume @yeastplume 16:26 at some point we'll add grin developers to it

Gary Yu @garyyu 16:30 👍 I will submit an issue to remind you to change this,...