Build: Update version of grunt-autoprefixer devDependency.

The update includes a new version of Autoprefixer which now supports the `ms-touch-action` prop for IE10.
Run `grunt autoprefixer:core` to re-add the missing props in media-view.css.

git-svn-id: https://develop.svn.wordpress.org/trunk@27236 602fd350-edb4-49c9-b593-d223f7449a82