Round paddings of .container & .container-fluid to match .row's margins

fixes #16769: use a clearfix on the .modal-header instead of a min-height to avoid collapsing when only a dismiss button is available and no .modal-title

Show active buttons when form disabled

Fixes #16779: Add padding to jumbotron with outer container

fixes #16902: remove the .container-fluid from the grid system in modal example since it's doubling up padding

Multiple button input groups

Move help block docs up page, add `.help-block` to validation example

Confirmed that Edge still suffers from two IE11 bugs

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Simpler docs footer

Smaller local Expo screenshots

Remove http://crbug.com/309483 from the Wall of Browser Bugs

All current major browsers behave like Chrome here, so this bug is most likely invalid.
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Refs #16180
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Customizer: Clarify that Collapse requires Component animations

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Add support for Meteor 1.2

Bootstrap v3 does not currently claim to be compatible with jQuery v3

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[skip validator]

Fixes #16828
Closes #16865

Add a local jQuery fallback.

Shouldn't really happen, but China for example has blocked Google so this should help.

Update devDependencies.

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Add Wall of Browser Bugs entry for #16814

Closes #16814
Refs http://wkbug.com/147284
Refs http://openradar.appspot.com/21993128
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Remove #16473's entry from Wall of Browser Bugs