* Allow url(), attr(), none,... as breadcrumb divider
* Update breadcrumb divider docs

- Replaces CSS variables with their appropriate hex values
- Fixes the broken navbar transition by moving from 2D translates to using position
- Fix broken IE navbar toggler placement with some utilities (not necessary anywhere else, but necessary given flexbox quirks)

* Update Dashboard example

- Replaces .sticky-top on .navbar with .fixed-top
- Adjusts padding on main content area and sidebar to account for fixed navbar
- Move to padding in sidebar instead of top: 48px; fixes Firefox rendering issue
- Adds new .shadow utility for a little extra cherry on top
- Moves sticky styles to separate feature query ruleset to avoid IE rendering issues

* Add .w-100 to chart to fix IE horizontal scroll from label that extended past viewport

1. It's == "it is"

2. The subject of the sentence is "Only one" (not "these") so the verb must agree with it.

Feel free to do nothing with this change, use it, etc - I just saw this while reading through the code.

Uses orphans/widows trick from @fran-worley at https://github.com/twbs/bootstrap/issues/20925#issuecomment-333492739.

Fixes #20925.

Removes the .justify-content-between from a navbar form example given it's the default style. Instead, mention how to adjust this and link to flex utils.

Closes #25829, closes #25924

This reverts commit 70520855.

While the old one will keep working, better switch to the new one.

This reduces duplication and the chances to forget to update something.

Kept back karma-qunit and qunitjs because tests fail.