Takes telescope out of the Parked state.
ASCOM.DriverAccess (in ASCOM.DriverAccess.dll) Version: 126.96.36.199 (188.8.131.5239)
The state of Tracking
after unparking is undetermined.
Valid only after Park
Applications must check and change Tracking as needed after unparking.
Raises an error if unparking fails. Calling this with AtPark
= False does nothing (harmless)