transfer file names automatically

[FND]

When copying individual files, it'd be nice if faucet-static could automatically determine the target file name based on the source:

    source: "jquery/dist/jquery.min.js",
    target: "./dist/"

⇒ ./dist/jquery.min.js

This behavior might kick in based on the target's trailing slash (not necessarily intuitive and potentially confusing?) or if target is a directory (which might conflict with such directories being created automatically).