Cache / Folder watch / list links

[peminator]

it would be nice to have a way to provide reliable "last modified" timestamps for the most recent of files addded, including their imports if local files, so ppl can easier build logic arounf it to cache the once computed content, if any of the files or linked imports changes

and lib already is parsing paths, so would be nice to have a simpe timestammp returned, or array of detected paths, so user can implement ownc caching around...

or even if cache dir defined, lib could "watch" if changes made, recompile only if needed, and add the NOT MODIFIED headers implemetation if browsers try to check