Sequencer commands

A general issue in defining sequencer scripts is that the way it works might depend on the specific state of the instrument, the detector or the telescope. This is especially an issue for scripts (for ToO or monitoring observations) which might be executed at any time, or when using scripts from previous observing runs. Therefore, there is some need to provide/define some general default setting. The original idea was to provide `setup-instrument' scripts which will set things to specific default values (e.g., for ALFOSC, all wheels to `open', full-window read-out and no binning for the CCD, the calibration mirror unit and FAPOL out of the light beam, the internal instrument focus set to 1810 and the relevant keywords cleared). However, it was noted that for FIES there is no real default instrument setting, while for ALFOSC or NOTCam there are actually different defaults for imaging, spectroscopy or polarimetry making this somewhat ill defined. So, beyond some basic (re)set commands like fies.setup-ccddefaults or notcam.setup-ima and notcam.setup-spec it was decided to not make specific scripts but to consider more basic commands/scripts that (re)set some defaults for specific parts of each instrument.