More robust detection of css animation support 

I rewrote script to implement more robust css animation support detection according to the [MDN guide](https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Using_CSS_animations/Detecting_CSS_animation_support). Currently it just  uses ua-sniffing which is not reliable: Opera 12.17 supports css animation without prefix and NOT supporting prefixed properties, so generated styles just not working there, and also in future script will force browsers to use prefixed properties even if animations will be supported there without prefix already.

Now script detects if the browser supports animations, and sets prefixes only if they actually needed.

P.S.: Not sure how build process is done so I also updated minified version of the script using http://jscompress.com/