fontchooser: Use absolute size for the preview text in the list
fontchooser: Use absolute size for the preview text in the list

With absolute sizes, Pango is way better at getting the actual sizes of
the fonts to match up. It's a bit harder to compute a proper value for
this, whcih makes the code ugly, but as long as it works better...

Adamovskiy/gtk,Adamovskiy/gtk,Sidnioulz/SandboxGtk,ebassi/gtk,davidgumberg/gtk,davidgumberg/gtk,jigpu/gtk,chergert/gtk,ahodesuka/gtk,davidt/gtk,grubersjoe/adwaita,alexlarsson/gtk,ahodesuka/gtk,Distrotech/gtk2,jigpu/gtk,chergert/gtk,jessevdk/gtk,chergert/gtk,jadahl/gtk,Adamovskiy/gtk,davidgumberg/gtk,davidt/gtk,msteinert/gtk,jadahl/gtk,ebassi/gtk,bratsche/gtk-,Lyude/gtk-,Sidnioulz/SandboxGtk,davidgumberg/gtk,ahodesuka/gtk,alexlarsson/gtk,ahodesuka/gtk,bratsche/gtk-,davidgumberg/gtk,Lyude/gtk-,davidt/gtk,jadahl/gtk,jigpu/gtk,davidgumberg/gtk,jigpu/gtk,Sidnioulz/SandboxGtk,ebassi/gtk,chergert/gtk,bratsche/gtk-,grubersjoe/adwaita,davidgumberg/gtk,chergert/gtk,jadahl/gtk,Distrotech/gtk2,davidt/gtk,alexlarsson/gtk,alexlarsson/gtk,chergert/gtk,msteinert/gtk,Adamovskiy/gtk,ahodesuka/gtk,chergert/gtk,davidt/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,Sidnioulz/SandboxGtk,Adamovskiy/gtk,Adamovskiy/gtk,jessevdk/gtk,msteinert/gtk,msteinert/gtk,alexlarsson/gtk,Distrotech/gtk2,Lyude/gtk-,grubersjoe/adwaita,jessevdk/gtk,Distrotech/gtk2,jadahl/gtk,Lyude/gtk-,bratsche/gtk-,jadahl/gtk,jadahl/gtk,msteinert/gtk,grubersjoe/adwaita,alexlarsson/gtk,chergert/gtk,Lyude/gtk-,msteinert/gtk,grubersjoe/adwaita,ahodesuka/gtk,bratsche/gtk-,ahodesuka/gtk,grubersjoe/adwaita,Lyude/gtk-,jigpu/gtk,Sidnioulz/SandboxGtk,jadahl/gtk,ebassi/gtk,Distrotech/gtk2,jessevdk/gtk,jigpu/gtk,jessevdk/gtk,alexlarsson/gtk,Lyude/gtk-,Adamovskiy/gtk,bratsche/gtk-,ebassi/gtk,ebassi/gtk,Distrotech/gtk2,jessevdk/gtk,jigpu/gtk,davidt/gtk,grubersjoe/adwaita,jessevdk/gtk,Adamovskiy/gtk,jigpu/gtk,alexlarsson/gtk,Lyude/gtk-,grubersjoe/adwaita,davidgumberg/gtk