Specify jQuery version explicitly

See http://hyper-text.org/archives/2014/07/dont_use_jquery_latest_js.shtml
Remove scheme from jQuery URI to use with both https and http
Load Twitter Bootstrap from CDN
Remove unused static files
Fix indentation of button to avoid included in <input>
Update Twitter Bootstrap and required jQuery
Migrate Bootstrap version from 2 to 3

According to http://getbootstrap.com/migration/
Make input type more semantic
Keep query words in input after search
Merge branch 'master' of github.com:ranguba/epub-searcher