Re: [RFC/PATCH 1/6] revert: libify cherry-pick and revert functionnality

> From: Stephan Beyer <s-beyer@gmx.net>
> 
> The goal of this commit is to abstract out "git cherry-pick" and
> "git revert" functionnality into a new pick_commit() function made
> of code from "builtin-revert.c".
> 
> The new pick_commit() function is in a new "pick.c" file with an
> associated "pick.h".
> 
> This function starts from the current index (not HEAD), and allow
> the effect of one commit replayed (either forward or backward) to
> that state, leaving the result in the index. So it makes it
> possible to replay many commits to the index in sequence without
> commiting in between.
> 
> This commit is made of code from the sequencer GSoC project:
> 
> git://repo.or.cz/git/sbeyer.git
> 
> (at commit 5a78908b70ceb5a4ea9fd4b82f07ceba1f019079)
> 
> And it contains some changes and comments suggested by Junio.
> 
> The original commit in the sequencer project that introduced
> this change is: 94a568a78d243d7a6c13778bc6b7ac1eb46e48cc
> 
> Mentored-by: Daniel Barkalow <barkalow@iabervon.org>
> Mentored-by: Christian Couder <chriscool@tuxfamily.org>
> Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
> Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
> ---