History of start 3 changes

In crates/backdrop/src/lib.rs, lines 266–384 on a9088323c39024e0c4098547ac234cd71589e7a4af0c6b92fd6a343648e85ff2. 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 266,384:crates/backdrop/src/lib.rs.