Writes the .dwg file data of this object. 

Returns eOk if writing was successful or an appropriate OdResult error code in the other case.

This function is called by dwgIn() to allow the object to write its data. When overriding this function: 1) Call assertReadEnabled(). 2) Call the parent class's dwgOutFields(pFiler). 3) Call the OdDbDwgFiler(pFiler) methods to write each of the object's data items in the order they were written.