History of start 3 changes

In crates/backdrop/src/lib.rs, lines 266–384 on b7d2b0b30b4ac9cf296a69413edcb0026af40ab263445dae89ecdb5030307526. 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.