title: javascript library to process complex 2D geometry
body: <p>Is there a good javascript library for complex geometry like:
  convex hull, 
  polygon intersection (polygons with holes), 
  polygon decomposition and
  polygon merging ?</p>
  
  <p>I heavily need polygon geometry, but it would be nice if there are more features...</p>
  
  <p>Greetings...</p>