Add MultiPolygon case for barycenter computing
Fix: align compass with north
   * [0,0,1] isn't always north anymore
Recompute histogram only when needed
Fix export button handler for HEALPixCutService
Fix fits style initialization
Add first SAMP row highlight implementation
   * TODO: find solution to get feature from row
Categorize layers
Add possibility to move/resize selection tool
   * Refactor pointInSphere/pointInRing to Utils
First commit of tool measuring the distance between two points