Make font match system

[Rich Jones]

Hey QZB!

Great plugin! I was going to make something like this for myself, but yours is just what I wanted.

I find the serif fonts you use quite difficult to read, however - it'd be nice if the fonts could match the host system application.

Thanks!

[Martin Bidlingmaier]

I don't think the font is explicitly set anywhere, so I think Dustman is already using firefox's default font.