Autoguider

The guide-star server should be changed for the (Pyraf) version that does not use IDL. Also, the guide star catalog used should be upgraded to a new version which is complete down to $\sim$18.5 mag to be able to fully profit from the improved sensitivity of the new camera. We also intend to improve the server such that it automatically finds a new star in case the current guide star moves out of the field of view when doing a combined telescope offset.