Fix Find/Replace-o; good catch, @FagnerMartinsBrack!

Problem introduced in 6b23a66c29c3613c6792a257aafa949c81746597
fix 'Calcuated' typo & run grunt; thanks @FagnerMartinsBrack

fixes typo introduced in 2b6ec389876fac116ae2a152e47be321632dd9ba
add loading class for mdo to style on customizer
Merge branch '3.0.0-wip' of github.com:twbs/bootstrap into 3.0.0-wip
fixes #6159
panels
Merge pull request #9271 from liuyl/panels

refactor panels.less
navbar.less
Merge pull request #9273 from liuyl/navbars

navbar.less
Add <main> element

See:
http://www.w3.org/html/wg/drafts/html/master/grouping-content.html#the-main-element

http://www.filamentgroup.com/lab/the_main_element/

http://html5doctor.com/the-main-element/
Add <main> element

See:
http://www.w3.org/html/wg/drafts/html/master/grouping-content.html#the-main-element

http://www.filamentgroup.com/lab/the_main_element/

http://html5doctor.com/the-main-element/
Merge branch 'main-element' of https://github.com/kevinSuttle/bootstrap into main-element