fixes

OpenFlipper-Free#150
by initializing the colorStack also when the pickCache is used, as the
picking renderer reinitializes the colorstack.

widgets/glWidget/QtBaseViewerPicking.cc

@@ -405,6 +405,8 @@ int glViewer::pickFromCache( ACG::SceneGraph::PickTarget _pickTarget,
   rgba[2] = pixels[hit][2];
   rgba[3] = pixels[hit][3];
 
+  //initialize colorstack and translate color to index
+  properties_.glState().pick_init(true);
   std::vector<size_t> rv = properties_.glState().pick_color_to_stack (rgba);
 
   // something wrong with the color stack ?