Add grunt-autoprefixer to grunt tasks

[mrmrs]

Instead of maintaining mixins for things like box-shadow and transition - we should just implement as part of our build process via this grunt task for autoprefixer. It runs off of the info from http://caniuse.com which makes it much easier to maintain proper vendor prefixes. Less mixins seems worth the price of admission alone.

[zlatanvasovic]

I think no. Bootstrap doesn't need all the prefixes.

[hnrch02]

autoprefixer doesn't just add all the prefixes, it actually can be tuned very fine.

[zlatanvasovic]

I know, but is it really required? It disallows removal of specific prefix, when caniuse becomes outdated.

[hnrch02]

caniuse is updated every couple of days, I don't think that we'd need to worry about that.

[zlatanvasovic]

Ok then. We have to try. :)

[hnrch02]

It's definitely something @mdo and the rest of the team has to decide.
/cc @cvrebert @juthilo

[mdo]

I'm down with it. I'd love for mixins to be only for code snippets and not prefixing. We can deprecate any of those mixins and switch to the autoprefixing, but I wonder if there would be any kind of conflict in that?

Would also be super cool to see a list of what can be switched over and what can't.

[mdo]

Done! #12670

[hnrch02]

🎆 🎉 🎊