WIP: enable zst compression using new compress= kwarg
FIXME: The one-liner expression that many scripts have to pass to `write_filename` will become unwieldy as the number of available compression methods grows from 1 to 2 or even more. Instead of this: ```python write_filename( filename, compress = compress = 'gz' if (options.output or "stdout").endswith(".gz") else False ) ``` this patch proposes a new `compress_for_filename` helper function: ```python write_filename( filename, compress = compress_for_filename(filename) ) ``` However, even this breaks the DRY principle.