Updated iOS and Android icons / launch images to more updated specificat...

...ions.  NOTE: Android build process renames 'drawable-xxxhdpi' to 'drawable-640dpi' (you can't just have 'drawable-640dpi' instead :/), so any apps that wish to replace that icon must have it placed in their 'icons/drawable-640dpi' folder, and not a 'drawable-xxxhdpi' folder.

Deleted some pre-shipped icons from some example projects as they shouldn't have been there.