Merge branch 'fixColorStackCompat' into 'master'

use glColor in compat mode for the colorStack

See merge request !84

libs_required/ACG/GL/ColorStack.cc

@@ -242,7 +242,8 @@ bool ColorStack::Node::setIndex (size_t _idx) const
 {
   if (colorStartIdx_ && colorStartIdx_ + _idx < colorEndIdx_)
   {
-    //glColor(translator_->index2color(colorStartIdx_ + _idx));
+    if(ACG::compatibilityProfile())                               //only change glColor in compat mode as shader pipeline 
+      glColor(translator_->index2color(colorStartIdx_ + _idx));   //renderer on core profiles does not rely on glColor
     return true;
   }
   return false;