Removed duplicated class change from migration instructions

don't use nonstandard window.location.origin in customizer JS

See https://github.com/twbs/bootstrap/issues/7398#issuecomment-27617890 for details.
Thanks @martinburger

Use nesting for .placeholder()

& > == >

Update customizer.js

Update README.md

Row 13 link update to tag v3.0.1

Added navigation role to example navbars

As per the docs:
http://getbootstrap.com/components/#navbar-default

  modified:   examples/carousel/index.html
  modified:   examples/jumbotron/index.html
  modified:   examples/navbar-fixed-top/index.html
  modified:   examples/navbar-static-top/index.html
  modified:   examples/navbar/index.html
  modified:   examples/non-responsive/index.html
  modified:   examples/starter-template/index.html
  modified:   examples/sticky-footer-navbar/index.html
  modified:   examples/theme/index.html

remove unused `{{ page.base_url }}` variables, and fix the urls

Combine multiple .thumbnail > img styles

Change tense to imperative

Matches this comment with the commit messages and other comments.

JS comments pointed to new documentation

Add -moz-osx-font-smoothing

Remove execute permissions on fonts files.

Ditch amp