Allow setting a custom scaling factor

[ibrahima]

This is useful for not-quite HiDPI systems, which could also use toggleable scaling, but not by 2x.

Also uses the new Jetpack SDK.

Got icons from FontAwesome, I think this should be okay according to their license.

[rubo77]

I cannot test this due to "no-time", but if you tested it thoroughly, I could accept this and see what happens.

any suggestions, or other reviewers for this?

[rubo77]

You are welcome to create your own fork of my addon and publish it on mozillas addon-site. If it works, I would refer to yours as successor and close my addon development for this there

[ibrahima]

Haven't really tested it thoroughly, but it works for my use cases. I guess I also don't really have the time to maintain this addon so I'd prefer to merge this into your branch, though perhaps not right away. I need to figure something out about icon coloring (since Firefox Developer Edition uses a dark theme, I want to make sure the icons show up as white on that, but I don't know how to do that yet and haven't had the time to really look into it).

For now I was mostly just curious as to whether you would accept a change like this. It's pretty straightforward, the configuration option appears in about:addons under preferences for this addon, and then that replaces the fixed 2x scaling option.

[rubo77]

At the moment in new Firefox versions, this addon doesn't have any effect on high-res-screens anyway, if you have set global scaling in Ubuntu on x2. Firefox obeys this scaling if it has set default -1.