3. Use some convoluted cond-expand clause to match against values of X
(as in 5.X) as an attempt to prevent the deprecation warning and
undefined variable errors.
Don't want to pull anyone into an NPM here, but we could have a tiny egg to abstract that away ("we" = anyone willing): exports current-process-milliseconds if >=5.3, otherwise renames current-milliseconds if <5.3. Shouldn't be too hard and egg authors are no longer inconvenienced with writing the cond-expand.
