Migrate to Bootstrap 3.1.1 and Twitter typeahead 0.10.2

First attempt to migrate from Bootstrap 2 to Boostrap 3, including the use of
Twitter typeahead.js.
Instead of maintaining local copies of those frameworks, the documentation will
now use copies on an external CDN (cdnjs.com).
CSS enhancements
Remove unneeded style
Re-enable top menu with Bootstrap 3 compatibility