v5.8.0

• Add DISP_E_* constants
• Add argError optional parameter to the Dispatcher.invoke method, allowing
  retrieval of the index of the first parameter in rgvarg that encounters an
  error, if applicable
• Update Dispatcher.set to accept a Pointer<VARIANT> for the value
  parameter
• Add byReference optional named parameter to the Dispatcher.set method,
  enabling property assignment by reference instead of by value