Solver, auto FOV

[han-k59]

If you enter for the FOV value 0, then astap_cli will try all FOV between about 10 degrees and 0.3 degrees height. It is slower because it goes through several FOV in steps of about 30% but could be helpful to find the correct settings for focal length & pixel size.

So what I suggest is in the long run to provide the option to force FOV to zero or allow it enter zero manually. After a successful solve the solver will report the actual FOV which could be used to manually or automatically update the settings.

Not urgent. Something for the future.