This whitelists various EE specific offenses of the various CodeReuse
cops.

Signed-off-by: Rémy Coutable <remy@rymai.me>

A new MR won't have an author necessarily, so use the current user in
that case.

Instead of performing `git log` for each file that's changed, do it for
all files at once. This stops git having to load large packfiles once
for each file in an MR.

This is always a suggestion, so the change in behaviour should be
fine. Increase the number of commits counted by squaring it, to allow
for the fewer calls to `git log`.

See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5401

Previously, this would pick the least-frequent contributors to the
changed files, rather than the most frequent.

This reverts commit 09ab819e, reversing
changes made to 041f3c27.

Previously, this would pick the least-frequent contributors to the
changed files, rather than the most frequent.