When changing the datetime (correctly) and pressing enter the map will display that specific timeframe
Remove space in date text field
Tweak particle settings

* Longer lines
* Slower (frameRate higher)
* More particles
* Smaller particles
* Slower fade out
whenjs for loading radar data and animation is no longer restarted when radar data is fetched
move of code block to (hopefully) prevent merge conflict
Interpolate on all points, with maximum of 5
Random particleAge is minimum half of the maxParticleAge
getting radar data and animating seperated so now there is a fluid change of direction of existing lines when the data changes
Give the option to provide dummy data
Set interesting startdate
Merge branch 'master' into interpolate

Conflicts:
	viz/index.html
	viz/js/birds.js
Merge branch 'master' into gh-pages