Move examples out of the main repo to twbs/bootstrap-examples

While examples are phenomenally useful and awesome for folks getting
started with Bootstrap, they don't really shine as well being buried in
the main docs. Moreover, having anything that's not core HTML, CSS, JS,
or documentation in the main repo seems to just get in the way.
Therefore, examples gets its own repo.

Specifically, we're doing the following:

* Deletes all example screenshots
* Deletes example layout
* Deletes example files
* Updates Getting Started docs to include only the template and a link
to the new examples project

All the examples and their history will be preserved in the switch.
Docs: create new callout classes
Adjust info callout, add callouts to docs

* Adjust the background-color of bs-callout-info to match danger and
warning in tone
* Convert all the callouts
* Change some callouts to info/warning
* Add new callout
Tooltip: apply position class before positioning
Remove changelog in favor of GitHub releases
Update readme to point previous releases to GitHub project releases (fixes #8508)
Fixes #8356: Move browser compatibility from wiki into real docs
Move license FAQs to the docs, add link to side nav
Fixes #8360: Add mention of IE compatibility mode to docs
maybe fix this old ass issue #5973
rebuild doe
Merge branch '3.0.0-docs-calloutfam' of https://github.com/juthilo/bootstrap-wip into juthilo-3.0.0-docs-calloutfam

Conflicts:
	docs/components.html
	docs/css.html
	docs/customize.html
Merge branch '3.0.0-wip' of github.com:twitter/bootstrap into 3.0.0-wip
fix broken docs callouts
Merge branch '3.0.0-wip' of github.com:twitter/bootstrap into 3.0.0-wip
fixes #6691
Merge branch '3.0.0-wip' of github.com:twitter/bootstrap into 3.0.0-wip
Merge branch '3.0.0-wip' into bs3_remove_examples

Conflicts:
	docs/_includes/nav-getting-started.html
	docs/examples/navbar-fixed-top.html
	docs/examples/navbar-static-top.html
	docs/examples/navbar.html
	docs/getting-started.html
link order
remove colophon include because there's only one layout using it now