show a heat map of crime activity

[radekstepan]

http://www.d3noob.org/2014/02/generate-heatmap-with-leafletheat-and.html

Fading away the "strength" just like we do currently.

[radekstepan]

One would need to rewrite the Leaflet plugin since if we want a "pulsating" view with crime having a ttl like points too, then we need to efficiently update the array from which the plugin reads. At the moment we would have to reset the input array for every day.