v7.4.1

FFI correctness fixes: ST unshiftAll (prepend), ST splice (full JS
semantics + returns removed), NonEmpty traverse1 (table nodes). See
purescript-lua/purescript-lua purescript#73, purescript#74, purescript#75.

v7.4.0 — Lua 5.1 FFI fix (table.pack/unpack/move → 5.1-safe; overlap-…

…safe move)