IRV: synchronize map and charts

[ptormene]

We would like to implement the following features:

• if you click on one region in the map, toggle its highlighting in the charts and in the tables (highlight it if it was not highlighted, or unhighlight it if it was highlighted)
• if you highlight one or more regions in a chart
  • highlight it/them in the other charts
  • highlight it/them in the map
• consecutive clicks on different regions add the clicked regions to the selection (and to the highlighting)
• SHIFT-click draws a bounding box and selects all features inside (highlighting them in the map)