* Thoroughly checked each icon for issues such as white background
(where not appropriate), aspect ratio, and white margins. Overall,
logos should look much more appealing now.
* Now most logos are in SVG. That means great visual quality together
with tolerable file size. That doesn't use .svgz just yet, which will
result in 50-70% size savings, see #2034.
* All icons have been updated to latest versions. We've had quite
a few outdated logos.