Better Icons

This Icon will look better on 1.3+

I didn't follow the default icon design guidelines from here because they're outdated: https://www.mozilla.org/en-US/styleguide/products/firefox-os/icons 
I'm following the new Icon design of 1.4 or 2.0+ (see it on the B2G Simulator) because it will look more consistent. Also, you don't really need a 512px icon, 284px is big enough.