Remove 48x48 icon; use 256x256 icon only.
Remove icons from the executable.
No need to call gtk_window_set_default_icon_name() anymore.
Add desktop file.
Add install and uninstall Makefile targets.
Update USAGE.md with installation instructions.
Thanks to @szszoke for figuring this one out!
Fixes#2.
Hard-coding a light background for route-label hovering didn't work
well with dark themes which have text in a light colour. Use
@theme_selected_bg_color as suggested by @szszoke.
Fixes#3.
Set the alignment on the socket picture to be center rather than fill
so if there's extra space available the image doesn't get expanded and
look awful.
Fixes#1.
