Merge pull request #1818 from Areloch/SimGroupPrefabFixup

Fixes up some erroneous behavior with Simgroup parentage.

Engine/source/gui/controls/guiTreeViewCtrl.cpp

@@ -4113,10 +4113,20 @@ void GuiTreeViewCtrl::onRenderCell(Point2I offset, Point2I cell, bool, bool )
       {
          if ( pGroup != NULL)
          {
-            if (item->isExpanded())
-               item->mIcon = SimGroup1;
+            //Check if we're a SceneObject, and pick the default icon as appropriate
+            
+            if (pObject->getClassName() != String("SimGroup"))
+            {
+               item->mIcon = Icon31;
+            }
             else
-               item->mIcon = SimGroup2;
+            {
+               //If we're purely a SimGroup, pick our icon.
+               if (item->isExpanded())
+                  item->mIcon = SimGroup1;
+               else
+                  item->mIcon = SimGroup2;
+            }
          }
          else
             item->mIcon = SimGroup2;

Engine/source/gui/worldEditor/worldEditor.cpp

@@ -3631,7 +3631,18 @@ void WorldEditor::makeSelectionPrefab( const char *filename )
       {
          for ( S32 i = 0; i < grp->size(); i++ )
             stack.push_back( grp->at(i) );
-         cleanup.push_back( grp );
+         
+         SceneObject* scn = dynamic_cast< SceneObject* >(grp);
+         if (scn)
+         {
+            if (Prefab::isValidChild(obj, true))
+               found.push_back(obj);
+         }
+         else
+         {
+            //Only push the cleanup of the group if it's ONLY a SimGroup.
+            cleanup.push_back(grp);
+         }
       }
       else
       {