Fixup for 365db6e3
/fyi @mdo
[skip sauce]

Wasn't able to reproduce in iOS 9.2.
So remove its entry from the Wall of Browser Bugs.
Refs #14708
[skip sauce]

Fixup for 27ba4beb
/fyi @mdo
[skip sauce]

Refs #19102
[skip sauce]

Fixup for #19105
[ci skip]

- Switch from width to max-width for all widths to avoid scaling outside viewport bounds
- Rejigger the media queries for a more logical breakpoint for the large and small modal sizes
- Avoids changing the width of the default modal (nullifying #17794 and fixing #17581)

- Using the grid classes, they still need clearfixes since rows aren't injected between them all
- Update docs to fix broken classes

- Make it an explicit class instead of qualifying with elements (.list-group-item-action)
- Rearrange the entire file for more straightforward flow
- Fix text-decoration bug as a result of the reorder
- Switch from h4's to h5's in docs
- Update docs to merge anchors and buttons sections; clearify usage guidelines there, too
- Nullify #17479 in the process

- Both classes do about the same thing, but with different names
- Clarifies docs for .m-x-auto requiring a fixed width block element for it to work
- Add missing heading for clearfix section in docs (unrelated)

Strip out .err from our syntax highlighting styles because it fucks up our placeholders in code snippets

- Flexbox responsive behavior fixed with specific .col-{breakpoint} classes now added
- Dropped the make-col mixin in favor of a column-basics placeholder that we can extend across our grid infrastructure
- Updated docs to use required .col-xs-12 (as a safeguard for when folks enable flexbox mode--this isn't necessary in default grid mode)
- Update flexbox grid docs to include responsive docs, tweak some other bits too

flip things around again, no more base class, try out some new stuff to keep responsive flex grid working