Refactor navs: new classes, remove separate pills & tabs files, drop justified nav because it never really worked

Drop the deprecated .visible-* classes (because we replaced them with .visible-*-block, -inline-block, -inline

Conflicts:
	dist/css/bootstrap.css.map
	dist/css/bootstrap.min.css
	docs/dist/css/bootstrap.css.map
	docs/dist/css/bootstrap.min.css

Docs: Refactor to use .less file instead, importing Bootstrap vars and mixins, and cleaning all the things up

Update browser support section to remove glyphicons in tables; also remove ie8 and font-face section

rems: update breadcrumbs to use new sizing; improve variables by renaming @breadcrumb-separator to @breadcrumb-divider; change up colors