originfox per Icewind

Store the download url and referrer in the "user.xdg.origin.url" and "user.xdg.referrer.url" extended attributes.

Installation

• Download the host binary from the
  releases and place it
  somewhere permanent.
• Run /path/to/downloaded/originfox install-manifest firefox to install the
  native messaging manifest.
• Install the
  firefox addon.

Privacy concerns

Note that the the information this stores with the files is potentially
sensitive information. While sharing the files online will not preserve the
extended attributes, users should still be aware of the potential issues with
leaking download locations.

Supported platforms

This is currently on tested on Linux, if somebody is interested in using it on
another operating system and wants to help test feel free to open an issue.