Allow the user to control the verbosity of merge-recursive.

Allow the user to control the verbosity of merge-recursive.

Junio C Hamano <junkio@cox.net> writes:
>
> I think the output from merge-recursive can be categorized into 5
> verbosity levels:
>
> 1. "CONFLICT", "Rename", "Adding here instead due to D/F conflict"
> (outermost)
>
> 2. "Auto-merged successfully" (outermost)
>
> 3. The first "Merging X with Y".
>
> 4. outermost "Merging:\ntitle1\ntitle2".
>
> 5. outermost "found N common ancestors\nancestor1\nancestor2\n..."
> and anything from inner merge.
>
> I would prefer the default verbosity level to be 2 (that is, show
> both 1 and 2).

and this change makes it so.  I think level 3 is probably pointless
as its only one line of output above level 2, but I can see how some
users may want to view it but not view the slightly more verbose
output of level 4.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>