provides a flexible orderable plugins render_filename with entrypoints

Flexible orderable plugin system with entrypoints to extend or override render_filename. Multi-registration available, specific target callable with -r, --rdr-fname-plugin-target cli option.
Long version here : https://github.com/jpcw/mr.bob/blob/03aecc4d16c54fa0964544a978128223d7d7d345/docs/source/pluginauthor.rst