Changes the Android app icon.

Yep, it's slightly less awful. Yep, it's slightly more in line with the icon
style guidelines at [1]. Nope, I'm not switching from programming work to
graphics work any time soon.

Lastly, yep, the 512px version is blown up from the source material, which is
just 320px. Always a great idea, but hey, if CSI:Miami can infer pixels that
aren't there, so can I. Actually, I believe MacGyver did it first, but I
digress.

[1]: http://developer.android.com/design/style/iconography.html#launcher