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
Fix form-control-feedback position when label has sr-only class
Fix indent
added bower reference to main less file
Add documentation for using optional icons with sr-only labels
Add nested kbd element styles for actual keys or inputs
Dropdown menu in justified button-group

It seems that dropdown-menu in justified button-group appears at the far
left of the group. Check the problem in [Bootstrap
site](http://getbootstrap.com/components/#btn-groups-justified).
#11464 - Fix JS noConflict mode - Refactor all plugins to use an internal reference to the jQuery plugin, because in noConflict mode you can never expect to be defined on the jQuery object
fires closed.bs.alert *after* DOM detach()

fires closed.bs.alert *after* element is removed from DOM.
Previously it fired while the element was still attached.
add script to warn folks trying to test old IE using IE's unreliable emulation modes
remove semicolons :'-(
add IE warning scripts to linter config
Fixed navbar radius of example at docs
Document that @import-ing Bootstrap can break the icon font path

Addresses part of #13429.
fixes https://github.com/twbs/bootstrap/issues/13367

Second color stop value should be percentage instead of decimal value.
Update JSZip to v2.2.1.
Update holder.js to v2.3.2.
Run `grunt`.
Update type.less

For better readability on mobile devices
Merge pull request #13435 from twbs/doc-less-import-glyphicons

Document that @import-ing Bootstrap can break the icon font path