CSS3 3D transforms for Carousel aren't used in Firefox

So, it turns out that the media query we're using (

Line 29 in 72a91b0

@media all and (transform-3d), (-webkit-transform-3d) {

) evaluates to false in Firefox. (Also, the unprefixed transform-3d media feature doesn't seem to exist; there's only -webkit-transform-3d)
Testcase: http://jsbin.com/lewuza/5/edit
I'm thinking we could duplicate the styles in an @supports feature query, which Firefox does support (again, see testcase).

Looks like this would require less/less.js#2473, but there hasn't yet been a Less.js release since that PR was merged.

@mdo You okay if we punt this to v4 since it's an enhancement?

Yup!

Reopening for v4.

@cvrebert You have a commit referencing this issue—is that branch ready to be opened as a PR?

No, that commit was against v3.