Merge branch 'master' into 3.0.0-wip

Conflicts:
	Makefile
	README.md
	component.json
	docs/assets/css/bootstrap-responsive.css
	docs/assets/css/bootstrap.css
	docs/assets/js/bootstrap-affix.js
	docs/assets/js/bootstrap-alert.js
	docs/assets/js/bootstrap-button.js
	docs/assets/js/bootstrap-carousel.js
	docs/assets/js/bootstrap-collapse.js
	docs/assets/js/bootstrap-dropdown.js
	docs/assets/js/bootstrap-modal.js
	docs/assets/js/bootstrap-popover.js
	docs/assets/js/bootstrap-scrollspy.js
	docs/assets/js/bootstrap-tab.js
	docs/assets/js/bootstrap-tooltip.js
	docs/assets/js/bootstrap-transition.js
	docs/assets/js/bootstrap-typeahead.js
	docs/assets/js/bootstrap.js
	docs/assets/js/bootstrap.min.js
	docs/index.html
	docs/templates/pages/index.mustache
	js/bootstrap-affix.js
	js/bootstrap-alert.js
	js/bootstrap-button.js
	js/bootstrap-carousel.js
	js/bootstrap-collapse.js
	js/bootstrap-dropdown.js
	js/bootstrap-modal.js
	js/bootstrap-popover.js
	js/bootstrap-scrollspy.js
	js/bootstrap-tab.js
	js/bootstrap-tooltip.js
	js/bootstrap-transition.js
	js/bootstrap-typeahead.js
	less/bootstrap.less
	less/responsive.less
	package.json

docs/assets/js/bootstrap-modal.js

@@ -148,7 +148,7 @@
       }
 
     , removeBackdrop: function () {
-        this.$backdrop.remove()
+        this.$backdrop && this.$backdrop.remove()
         this.$backdrop = null
       }