Allow FileObject.diffs to be set

(cherry picked from commit 71204611f7f22cfa963abea83cb67ff4c76a162a)
Add flag to require content hash match in file rename detection

(cherry picked from commit ecea49e56783a2c471ec7fb25ab5c3b5a12ce403)

Conflicts:
	python/make_differential_dfxml.py
Add count of renamed files that have matching content hashes

(cherry picked from commit f7ea02dd9aeb63d15ca8de176024022799c039c4)