merge-ort: split "distinct types" message into two translatable messages

merge-ort: split "distinct types" message into two translatable messages

The word "renamed" has two possible translations in many European
languages depending on whether one thing was renamed or two things were
renamed. Give translators freedom to alter any part of the message to
make it sound right in their language.

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>