Make autoprefixer browsers fixed

BS3 commits: 3f68c40ac1011059ad0e3a7098bc1c75e4cd92bc
popovers.html: fix typo: "Dimissmisable"

BS3 commits: 5b9e2bf1265eb50c0d4105b2eb3da12280c37430
Fix dismissible spelling

BS3 commits: 128e52ff29be0f275bb92693c9db3ba34d5c003d