changed attr('data-target') to data('target');

this will extend js interface, to be possible to setup targets for tabs as 
    var content=$('<div class="tab-pane">',{text: 'content'});
    var tab=('<li>',{html: $('<a>',{text: 'Main options'})}).addClass('active').data({target: $main,toggle: 'tab'}).appendTo(tabs);
adding required attribute for example signin form
move to separate about page
Dropdown in panel header does not inherit its colors

Fix for issue #10627
Removed the unnecessary override and the !important from .wrap

In the sticky footer example there were some weird stuff..
Same fix for the navbar example of sticky footer
Use bootstrap.less file order in Customizer

Appending stylesheets by iterating the `__less` Hash creates an order
that is not the same as 'bootstrap.less'.

Some stylesheets like 'component-animations.less' and 'modals.less' have
selectors with matching specificity, and so file order decides which
style wins. This causes issue #10030 by putting `.fade.in` after
`.modal-backdrop.in` and gives the backdrop a higher opacity than
intended.

This change uses the Less ordering in 'bootstrap.less' to generate the
final stylesheets in the Customizer to make sure customized file
ordering matches the distribution file order.

Fixes #10030
Better documentation and optimized examples for grid classes
Update Gruntfile.js fixing undefined jQuery check

The check to see if jQuery was defined as incorrect causing the "Bootstrap requires jQuery" message to only be displayed if jQuery is defined and has a value which equates to `false`.
Added abridged form of 'What's included' docs to README
Merge pull request #10863 from DeanMarkTaylor/patch-2

Update Gruntfile.js fixing undefined jQuery check
rm unnecessary backslashes from jqueryCheck
Moved 'getting started' link out of 'What's included' section in README
Apply help-block class to help text in customize.html
Update qunit dependency
Merge pull request #10869 from ZDroid/patch-2

Update qunit dependency
Remove .ruby-version due to https://github.com/twbs/bootstrap/commit/4f20a29c329aa58919919426cbd2190fabfdb723
Remove "Remove margin on the body" from base css docs

Normalize did that.
also use .col-sm-* in other .form-horizontal example for consistency
use .col-xs-* in "Forms: Column Sizing" docs so more responsive