Add docs readme icon
 Fix link to File structure anchor
Add transition-duration mixin
Merge branch 'sparanoid-transition-duration' into 2.3.0-wip

Conflicts:
	docs/assets/img/bootstrap-docs-readme.png
Merge pull request #6407 from aurnik/master

Fix link to File structure anchor
Popovers are now flexible width:

* Instead of a fixed width, we use max-width
* Width has been increased from 240px to 280px
* Added ability to hide the title via CSS :empty selector if no title is provided
Basic keyboard accessibility CSS tweaks

Mostly doubling-up :hover styles to also cover :focus, as a first step
to making the framework more keyboard-friendly.
Additionally, fixed two small markup issues in the docs/examples to
make the "Learn more" large primary button-styled links
keyboard-focusable (as without href they're treated as non-tabable
anchors).
update docs to reflect #5786
Update composer.json

target-dir is not needed. All it does, is nest everything another level deeper. It should only be used for completing psr-0 paths.
Removed touchstart from bootstrap-dropdown.js.
replaced tabs with spaces
Corrected carousel arrows to active.#6494, #6489

Corrected the carousel arrows to active on resizing the browser window.
add sticky footer with navbar
Merge branch 'Justin-John-master' into 2.3.0-wip
Merge branch 'aronwoost-patch-1' into 2.3.0-wip
Update docs/examples/fluid.html

Updated copyright to 2013
Update docs/examples/carousel.html

Updated copyright to 2013
Update docs/examples/hero.html

Updated copyright to 2013
Update docs/examples/marketing-alternate.html

Updated copyright to 2013
Update docs/examples/marketing-narrow.html

Updated copyright to 2013