update customize.html to Bootstrap 2.3.0
update extend.html to Bootstrap 2.3.0
update example images to Bootstrap 2.3.0
update getting-started.html to Bootstrap 2.3.0
update index.html to Bootstrap 2.3.0
update javascript.html to Bootstrap 2.3.0
update scaffolding.html to Bootstrap 2.3.0
add select2 back