Remove support for old browsers

[romamatusevich]

According to the issue: https://github.com/paulirish/css3please/issues/123

Remove:

1. -webkit-border-radius
2. -webkit-gradient, -moz-linear-gradient, -o-linear-gradient
3. -moz-transform, -o-transform
4. -moz-transition, -o-transition
5. -moz-animation, -o-animation, @-moz-keyframes, @-o-keyframes
6. -o-tab-size

Leave:

1. -webkit-box-sizing: according http://caniuse.com/#search=box-sizing Safari 5.0 and Android 2.3-3 use -webkit prefix.

Add:

1. Comments about Opera 15+ support to -webkit prefixed properties: -webkit-transform, -webkit-animation.
2. Update comment for -webkit-transition support: Safari 3.2-6 and add Android 2.1+, iOS 3.2-6.1.

[paulirish]

This is an epic PR. thank you so much. :dancer:

want to follow up with a commit to change the Opera 12* to "Opera" ?

After that i'll merge the eff out of this.

thanks so much for this one @romamatusevich

[romamatusevich]

Always pleasure!

Update "Opera 12*" to "Opera" for: background-image: linear-gradient, transform: rotate, transform: scale, transition, animation.

Also I can remove all comments about Opera < 15 and instead of "Opera 15+" use "Opera". What do you think about it?

[asuh]

This is awesome! I was wondering when it would happen. Can I suggest an update to box shadow as well? the -webkit-box-shadow prefix is not needed for Android 4+. Thus, we can look at getting rid of it all together since the other requirements match the border radius prefix.

[romamatusevich]

I suggest to leave -webkit-box-shadow. So, remove only support for Android < 2.3

[paulirish]

Merged!