Partially revert marking of copies as direct

Summary:
The other true is correct (and I think we can fix the scaling issues) but this one should be an indirect change. This prevents the branch from appearing in the history of every file.

(I misread this code and gave @vrana some bad advice originally. This is actually consistent with Mercurial and Git.)

Test Plan: Partial revert. I'll make this stuff testable.

Reviewers: nh, vrana

Reviewed By: vrana

CC: aran

Differential Revision: https://secure.phabricator.com/D4742