Remove external parameter name from JSON.{map,flatMap}()
Remove external parameter name from JSON.{map,flatMap}()

This makes it easier to compose functions like

    let ary = try json.getArray("foo", { try JSON.map($0, { try parse($0.getObject()) }) })

hpux735/PMJSON,hpux735/PMJSON,hpux735/PMJSON