use GLGraphics instead of direct GL if possible
fix sgratzl/org.caleydo.view.domino/issues#74 heatmap selection
simple api changes
more options for the idmapping descriptor + change loading order
 * fromPrimary .. should be the from type the primary idtype
 * toHumanReable .. should be the to type the human one
 * LOADING ORDER: mappings will be loaded before the data, which might
use them