History of CasFs::readlink 1 change

In crates/flow-casfs/src/main.rs, lines 243–248 on v0.2.0. 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 243,248:crates/flow-casfs/src/main.rs.