Target acquisition

The new permanent pointing offset option provided in the TCS was tested with TurPol and found to work well. The current telescope pointing being good, this allows the target to always come very close to or inside the TurPol diaphragms, speeding up TurPol target acquisition. To improve the system further the plan is to implement the existing `handset' interface used to center a star on a fiber in FIES, and use it to center the targets more quickly in the diaphragm.