Fix link to navbar doc
Fix corss link for sticky footer
Replace png img by holder.js in carousel example
remove unused img from previous commit
Improve responsiveness for tablet and below of navbar in carousel example

- Remove margin-top of navbar-wrapper
- Remove border radius of navbar
- Space out the carousel
Fixes #7462: add radial-gradient spec to mixin
Merge branch 'example-fix' of https://github.com/Boulox/bootstrap into Boulox-example-fix
refactor some of the carousel caption stuff to center it and tighten styles up; update carousel template to start to redo mobile first
fix that sidenav