Enabling new screen sizes

//FREEBIE
Rerendered Icon in iOS 7 and iOS 8 style.
It was rendered with a wrong and useless border before.

Added 3x Version for iPhone 6 Plus.
Removed wrong/unnecessary/ugly black border.
Removed 512x512 version. Since it is supported by iTunes Connect anymore.
Merge pull request #165 from abcdev/unuglify-icon

Unuglify Appicon