Fix string constructor of ObjectID

source/RobotAPI/libraries/ArmarXObjects/ObjectID.cpp

@@ -25,10 +25,14 @@ namespace armarx
                     << ", but got: '" << nameOrID << "' (too many '/').";
             _dataset = split[0];
             _className = split[1];
+            if (split.size() == 3)
+            {
+                _instanceName = split[2];
+            }
         }
         else
         {
-            // dataset is left empty.
+            // Dataset, instanceName are left empty.
             _className = nameOrID;
         }
     }

source/RobotAPI/libraries/ArmarXObjects/ObjectID.h

@@ -14,7 +14,7 @@ namespace armarx
 
         ObjectID();
         ObjectID(const std::string& dataset, const std::string& className, const std::string& instancName = "");
-        /// Construct from either a name ("myobject") or ID ("mydataset/myobject", "mydataset/myclass/myinstance").
+        /// Construct from either a class name ("myobject") or ID ("mydataset/myobject", "mydataset/myclass/myinstance").
         ObjectID(const std::string& nameOrID);