Port this extension to Firefox

[ceilican]

The port should be done in a way that both versions (Chrome and Firefox) share as much code as possible, in order to facilitate maintenance.

[sudeepb02]

I would like to work on this issue as a GSoC project. However, I see that the extension has been partly ported to Firefox last year.

As of now, Firefox has implemented a WebExtension API which would be largely compatible with Chrome and Opera extension.
So most of the code would work with some minor changes in the base code.

[ceilican]

@sudeepb02 That's great! We are looking forward to receiving your proposal on this topic. As this is probably not enough to keep you busy during the whole GSoC coding period, you should also think about other things that you would like to do and include them in your proposal as well. And remember to submit some merge requests to show us your skills and engagement.