This replaces the "application" directory where were stored some common static pages

A separate filter page lets users search more precisely for events or organisations, in different formats

Event calendar better displayed on small screens: past events only visible when hovering over the current month

as recommended in RFC 3986 section C (ftp://ftp.rfc-editor.org/in-notes/rfc3986.txt)

Close #77

The parameter that can be used to have future *and* past events in the rss feed is renamed to `future`