Telescope related commands

Various improvements were made in relation to TCS commands that can be given through the observing system.

To make scripting of observations easier, the tcs.guide-object command has been updated to allow for optionally defining the field rotation. It was noted that defining the PA give different rotator positions depending on the instrument and configuration (e.g., horizontal or vertical slit) used. In the above way you have the same capability in scripting mode as in command line mode (i.e., you will have to define yourself what field rotation to use to get a desired PA).

One observer had a problem identifying a target because the parameters for proper motion in the sequencer command `tcs.enter-object' where set to non-zero values by accident. To be more clear, the command shows on the screen what has been entered (object name, RA, Dec, Epoch, RA proper motion (arcsec/hour), etc) so one can see what parameters were specifically entered. Furthermore, the command was modified such that the values for proper motion and magnitude are only optional, and are automatically set to zero if not given.

Offset commands are provided to move the telescope with respect to the orientation on the detector. Especially if one uses non-standard field rotation angles (e.g., the parallactic angle) it is not obvious how the directions on the detector relate to RA and Dec. For convenience, separate commands (tcs.ra-delta and tcs.dec-delta) were made that moves the telescope in RA or Dec, independent of the specific orientation of the detector (e.g., this can be used to center a slit on an object which is positioned at a given offset from a nearby star).

A thing noted is that if you measure and set the telescope focus from the sequencer, the value is reset every time you run the instrument setup script (tcs.setup-tel-$<$instrument-name$>$) script for the same instrument (e.g., after having used an other instrument). The system has been changed such that if the system for an instrument is started up, the system value is set to the default telescope focus value, but all the instrument scripts have been modified to set the telescope focus to the system value that is defined during the on-going observing session, rather than the default value.

Only for ALFOSC there is a fully automatic focus routine, and this script (alfosc.focus) has been modified to update the system focus value to the value found from the script. The other scripts defining the telescope focus (alfosc.focuspyr, notcam.focuspyr, stancam.focus-auto and mosca.focus-auto) have been modified to print a line saying that once the telescope focus has been set, to execute a script (tcs.updatefocus) to update the system value for the telescope focus.