git-send-email: Ability to populate CC using more tags

[Manivannan Sadhasivam]

Hello,

Currently 'git-send-email' lacks the ability to CC people described using
tags such as Acked-by and Reported-by etc...

While doing a bit of googling, I found a patch from Joe [1] but that doesn't
look like made its way. And in that discussion I didn't see any real objections
for the patch intention apart from the usage of the term 'trailers'.

So I'm just curious if Joe or anyone has plan to resubmit it! If not I may
do that.

PS: 'bylines' as mentioned by Joe seems reasonable to me.

Thanks,
Mani

[1] https://lkml.org/lkml/2016/8/30/650