History of start 3 changes

In crates/backdrop/src/lib.rs, lines 266–384 on d7050703d2f4c830367a32398629c87fe74160c58d1937c32b71eb313d29517f. 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.