History of project 3 changes

In crates/oh/src/main.rs, lines 1284–1398 on image-check. 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 1284,1398:crates/oh/src/main.rs.