Development of Long-Acting Dopamine Transporter Ligands as Potential Cocaine-Abuse Therapeutic Agents: Chiral Hydroxyl-Containing Derivatives of 1-2-[Bis(4-fluorophenyl)methoxyethyl]-4-(3-phenylpropyl)piperazine and 1-2-(Diphenylmethoxy)ethyl-4-(3-phenylpropyl)piperazine