Document that uncollapsing the mobile navbar requires JS. Remove multiple navbar z-index callout

BS3 commits: f47510b1722f9ce654c293c7d9d5ab0828be1167,
72cfe877d8585054558cb83222d207159f854dd1
Add another newline to improve final code readability. Add .animation() mixin. Fixes 11206: remove left padding on first inline list item

BS3 commits: 4fac7b6d25953eeedf54eba98d3861afc8ed25de,
64ffed87a4809388eeab891cb7c43284393e12e2,
4cfe307abeee4f0193a0bcbc54aad08d1115b002
Add another newline to improve final code readability

BS3 commits: 4fac7b6d25953eeedf54eba98d3861afc8ed25de