History of checkpointer 2 changes

In crates/hub/src/tlog.rs, lines 748–765 on v0.9.5. 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 748,765:crates/hub/src/tlog.rs.