carousel: correctly reset when the slide event is prevented
Pass $element to offset top/bottom calc funcs

At the moment to make dynamic top offset calculator on multiple elements, one would write:

``` javascript
$('.my-affix').each(function () {
  var $el = $(this);
  $el.affix({
    offset: {
      top: function () { return $el.offset().top; }
    }
  });
})
```

This patch will allow to:

``` javascript
$('.my-affix').affix({
  offset: {
    top: function ($el) { return $el.offset().top; }
  }
});
```
Use correct directory name for bootstrap contribution
roll back version numbers to avoid broken links in docs and readme (fixes #12000)
Merge branch 'master' of github.com:twbs/bootstrap

Conflicts:
	docs-assets/js/raw-files.js
don't roll back that comment
Merge pull request #12001 from soundarapandian/fix_typo_contributing

Use correct directory name for bootstrap contribution
fixes #10236
if affixed top add scrollTop to it position.top
calculate and cache pinnedoffset independent of scrolling for initial load
Merge branch 'master' of github.com:twbs/bootstrap

Conflicts:
	dist/js/bootstrap.min.js
	docs-assets/js/raw-files.js
fixes #10283
Merge branch 'slide-event-reset' of git://github.com/Rowno/bootstrap into Rowno-slide-event-reset

Conflicts:
	js/tests/unit/carousel.js
fixes #10134 – dont use jquery offset directly because it uses sub pixel rendering
Merge pull request #10359 from ixti/patch-1

Pass $element to offset top/bottom calc funcs
note for #10486 add note about data-toggle dropdown dependency
Merge branch 'master' of github.com:twbs/bootstrap