Dump the type margin overrides in alerts for utils, document that particular example, sidesteps part of #18884

- Rename -height to -height-base to match other vars
- Drop use of -height across the board and rely on it to be inherited
- Adjust padding of .dropdown-header to account for different line-height of h6 heading element (this needs refactoring for variables and rems also)

Update shrinkwrap

Closes #19049

Travis CI: Disable npm's progress bar for speedier install

Update print styles to v5.3.0 of html5 boilerplate.

See https://github.com/npm/npm/issues/11283

https://connect.microsoft.com/IE/feedback/details/2274240/edge-edge-renders-an-svg-img-with-max-width-100-too-small
is fixed as of Edge 25.10586.0.0 (or possibly earlier).
Confirmed in https://github.com/twbs/bootstrap/issues/16915#issuecomment-175210482
Reverts #19010

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Fixes #19028

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When using a <label> as an .input-group-addon, there will be a default margin-bottom of .5rem via Reboot.
This will lead to undesirable whitespace below the label and the <input> will become taller than needed. By removing the margin, it will play nice with <label> elements.

Closes #19012

Bump Normalize so we can remove Reboot's input[type=search] box-sizing override

Popover docs: Fix section link to Tether.js docs
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Add $blockquote-border-width variable

Remove print-specific img max-width:100%; style so that Google Maps etc. print correctly

Apply word-wrap:break-word to Tooltips and Popovers

Bump SCSS-Lint, and `bundle update`

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Add Wall of Browser Bugs entry for #16915

https://connect.microsoft.com/IE/feedback/details/2274240/edge-edge-renders-an-svg-img-with-max-width-100-too-small
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Revert "fixes #17379: override search input box-sizing to match our global overrides"

This reverts commits 468a9d93 & 57998dc2.

https://github.com/necolas/normalize.css/pull/496 has made this override unnecessary.

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Bump Normalize to https://github.com/necolas/normalize.css/commit/fe567632afcf8afcf17925ab2a507ed87504cce8

So as to pull in https://github.com/necolas/normalize.css/pull/496

Remove print-specific img max-width:100%; style so that Google Maps and other widgets print correctly

See https://github.com/h5bp/html5-boilerplate/issues/1741
X-Ref: #1506

Add prefix to docs/index.html assets/img/sass.png

Replace inline HTML with markdown, rewording, and cleanup.
Closes #18984