Fixed nested tab elements li activation

Added closest li instead of direct parent so that you can nest multiple elements within tabs, such as button groups
Merge pull request #13191 from AshleyDawson/master

Fixed nested tab elements li activation
versions
grunt dist
Merge pull request #13578 from twbs/fat-versions

versions
grunt for raw js
Merge branch 'master' of github.com:twbs/bootstrap
grunt
grunt
no more concurrency
unfuck the gruntifle
Tweak JS style and the relevant JSHint and JSCS checks.
Comply to the new style.
Remove `laxbreak`.
Remove `boss`.
Enable `es3`.
Switch to using plain `if/else` statements when there's no assignment.

The minizer outputs the same code anyway, and this has better readability.
Minor style tweaks.
More updates to the JSHint/JSCS options.
Fix failing tests.