Decouple web from API

[unho]

This means provide search results using only a JSON API. The web page holding the search form then can retrieve the results from the API and append the results in the very search page. That way the search page can be served as static HTML and we already have an API capable of feeding CAT tools.

Pushstate is essential. It must be possible to be able to share specific search URLs with other people.

Depends on #23