ag/rebase-i-in-c, was Re: What's cooking in git.git (Jul 2018, #02; Wed, 18)

> * ag/rebase-i-in-c (2018-07-10) 13 commits
>  - rebase -i: rewrite the rest of init_revisions_and_shortrevisions in C
>  - rebase -i: implement the logic to initialize the variable $revision in C
>  - rebase--interactive: remove unused modes and functions
>  - rebase--interactive: rewrite complete_action() in C
>  - sequencer: change the way skip_unnecessary_picks() returns its result
>  - sequencer: refactor append_todo_help() to write its message to a buffer
>  - rebase -i: rewrite checkout_onto() in C
>  - rebase -i: rewrite setup_reflog_action() in C
>  - sequencer: add a new function to silence a command, except if it fails
>  - rebase-interactive: rewrite the edit-todo functionality in C
>  - editor: add a function to launch the sequence editor
>  - rebase--interactive: rewrite append_todo_help() in C
>  - sequencer: make two functions and an enum from sequencer.c public
> 
>  Piecemeal rewrite of the remaining "rebase -i" machinery in C.
> 
>  Expecting a reroll.
> 
>  The early parts of the series seem solidifying; perhaps with a
>  reroll or two, they become 'next' material?