title: Leaflet heatmap based on value not quantity
body: <p>I got some thousand points containing weights. 
  Many of those points have (more or less) the same coordinate and I want to visualize those points on a leaflet map using absolute coloring of the map. (Same coloring for a point at every zoom level)
  I tried using leaflet.heat but it seems to be adding up the values (resulting in everything colored red) and does relative rendering.</p>
  
  <p>It would be ideal if it would use the average or maximum of the provided weights for rendering a heatmap.</p>
  
  <p>Anyone has an idea how this could be done quickly? </p>