64 bit version of TfcTreeView does not write or read the "Data"-property

The 64 bit version of TfcTreeNode.WriteData does not write the Data pointer and TfcTreeNode.ReadData simple sets the Data pointer to nil. This seems to be by design to get a backward compatibility for saved TfcNodeInfo data.

This behaviour results into a problem in the following case:

1. Generate the treeview content with fcTreeView.Items.AddChildObject(..., SomePointer) before the form becomes visible. SomePointer will be assigned to Data pointer.
2. Call MyForm.ShowModal. This will (re)create the window, calling somewhere WriteData and ReadData. In the 64 bit version, Data is lost!

This will also happen on any recreation of the window/dialog at runtime.

I suggest to use one of the TfcNodeInfo.DummyPad bytes/bit as a flag to signal that in the saved data a 64 bit pointer will follow instead of a 32 bit pointer. On reading, a 32 bit version could ignore the 64 bit pointer and vice versa, but a 32 bit version will read the 32-bit-pointer and the 64 bit version will read the 64 bit pointer, which is essential at runtime.

A second suggestion/solution is a new boolean property in TfcTreeView which advices TfcNodeInfo to save the 64 bit Data pointer, for the price of losing backward compatibility.