There is a similar add-on called Local Load
There is a similar add-on called "local load" for firefox available, I am not sure if you are aware of it.
http://www.getlocalload.com/ https://addons.mozilla.org/en-US/firefox/addon/local-load/ it seems to be GPL2 and the last update was in February 2013
There are some old issues that are still not fixed https://addons.mozilla.org/en-US/firefox/addon/local-load/reviews/
There is also an additional userscript available: http://userscripts-mirror.org/scripts/show/87361
Maybe it could help you, e.g. to solve bug #16