History of Engine::fit 3 changes

In crates/backdrop/src/lib.rs, lines 60–76 on 6246d1e51f4fdb99485662612d4148901d1456d34c65f0ecf80643da769d634e. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 60,76:crates/backdrop/src/lib.rs.