developer.apple: "Animating CSS Transitions" only uses -webkit- prefixes

[dstorey]

URL: https://developer.apple.com/library/safari/documentation/internetweb/conceptual/safarivisualeffectsprogguide/AnimatingCSSTransitions/AnimatingCSSTransitions.html Google position: 9th (webkit-transition-duration)

Issues:

• Only uses webkit prefixes in text and demos. Safari now supports unpefixed, so can be added. Stops it working in non-webkit browsers

Fixes:

• Add unprefixed versions