Update dependencies.

BS3 commits: dc7da296e4f658a32c618b9b01bb00645c272be8
Turn off clean-css' advanced optimizations.

BS3 commits: 25ca51319b016bc4e42e1ba882d6f191e001d65d
Run `grunt`.

BS3 commits: 15c63fa137114dd660e48b00dc566246f5557bb9