fixes 9318

BS3 commit  89b3cb0dacd71fc7b20e125851f05f9ed266b50d
fixes 9348 by ditching a comment

BS3 commit 1ff1dfb2bd031832c725c146deb8b7363cfeadf5
code and pre vars

BS3 commit 8b76e0d0f0c5679f12935c4a3dad98917636702b
add a navbar margin var, but avoid the navbar-nav var because that should really be customizable

BS3 commit c2cfd3153bd181ebd05b347d04b3fff08fa1d890