Add an SVG of the official Galaxy Zoo logo.

This was provided by Kyle Willett under the GPL3:
https://plus.google.com/100123542880051296706/posts/WcjVd8zKT7e
ic_launcher.svg: Resave in Inkscape.

Actually, copy it into a new document and save it.
Something about the original SVG confused the Android Asset Studio.
It squashed the image about 50% horizontally.
Launcher icon: Generate PNGs from the SVG.

Using the Android Asset Studio:
http://romannurik.github.io/AndroidAssetStudio/icons-launcher.html#foreground.type=image&foreground.space.trim=1&foreground.space.pad=0&foreColor=33b5e5%2C0&crop=0&backgroundShape=bevel&backColor=ffffff%2C100