If the range header is passed, node-static supports resuming the file.
Currently it can only handle one range per file, so no bytes=100-150,200-250
and it can't do resume when multiple files are requested in one request
If the pathname is passed as null, the file path will be joined with '.'
But if the root and the process current directory are not the same, this
will not work, since we don't want to search the current directory, we want
to search the root