Tomeu prefers ' for strings, so let's use it wherever we don't have a good
reason to use ".
Reviewed-by: James Cameron <quozl@laptop.org>
Acked-by: Simon Schampijer <simon@laptop.org>
CC: Aleksey Lim <alsroot@member.fsf.org>
the icon rendering part. The plan is to share this code
with CanvasIcon once it has all the necessary features.
Also cleanup the API by just reusing gtk.Image icon_name
and file properties.
