Split json from main index.{html,js} files

A new API is introduced (/api/event/list/?format=json), and the index page is changed so it uses the API to retrieve events data. During events data retrieval an animated indicator is shown, and after receiving the data, the map is created and populated.
I actually meant to leave that one... in case of an error, it get's logged... not sure if we'll have much use for that, but still