miscellaneous additions to the focus routine

[PolishookDavid]

o Read previous good focus position from a log file. o focusTel should confirm that the mount is tracking, and track if needed. o focusTel should recover from large annulus by: read previous good position value. Check large range (28K to 38K ?). o Fit only the U-shaped curve and not flat sections. o When fit fails – try again. o Run checkWholeUnit after focusTel is done to set panel’s messages to green. o Investigate focus by temperature.

[EastEriq]

first one - see #48

Among the other desiderata:

• save in Unit.FocusData also the fitting parameters of the parabola. This way the despicable popping up focus plots can be completely reproduced using the content of FocusData, and, once for good, the popups can be forbidden, the Master units can be initiated with terminal=none (instead of silentx) and their processes be launched as services, detached from an X channel.