bug#8756: 23.3; vc-git.el doesn't use --follow argument in vc-git-print-log

[Dan Nicolaescu <dann@gnu.org>]

Steinar Bang <sb@dod.no> writes:

> When pressing `C-x v l' in a git versioned file with a long history,
> that had just been moved, I got just the single commit resulting from
> the move.
>
> If the vc-git-print-log command adds the "--follow" argument, the log
> printed by `C-x v l' is the full history of that file.
>
> Here's the documentation of --follow from the git-log man page:
>        --follow
>            Continue listing the history of a file beyond renames (works only for a single file).

I tried doing that at some point, but the result is not completely
functional, these commands do not work:
 "d" (log-view-diff)
 "f" (log-view-find-revision)  
 "a" (log-view-annotate-revision)

which means that the corresponding vc-git.el functions need updating.
If someone figures out what git commands/sequence of commands are needed
to implement these, then it should not be too hard to implement the
needed changes.