Instead of a dictionary/object, input file options are now specified
by a 'key=value' pair starting with '-' for options only applying to
the next URL or '-G' for Global options applying to all following URLs.
See the docstring of parse_inputfile() for details.
Example option specifiers:
- filename = "{id}.{extension}"
- extractor.pixiv.user.directory = ["Pixiv Users", "{user[id]}"]
-spaces="are_optional"
-G keywords = {"global": "option"}
- speed improvements, especially in the 'interpolate' function
- 'interpolate' now prioritizes base-level values if they exist
- "username" is chosen before "extractor.<category>.username"
- -u/--username & co can now override config-file values
