Formatting.
Simplify marker rendering event handler responsibilities.

Fix bug where already rendered unit markers were rendered twice when a
search was made in a situation where one of the search result units was
already on the map before the search.
Fix bug in p13n change listener.

Fixes #196.
Comprehensive event date formatting module.

Handles three different detail levels for different UI contexts,
three languages, multi-day events and event time displaying
peculiarities.