Add export-inkscape-icon.sh: Exports all the launcher icons from the .svg.
Add notification-icon.svg, exporter script, and exported .png files.

NOTE: Inkscape always displays the doc over a white canvas, so if the doc
is white shapes on transparent, you can't see anything!

WORKAROUND: I added a black background layer to view while editing. So hide
it, save the .svg, run the export script, unhide the background layer, then
save it again.