Pre-deployment release for PyPI

This version will be tested in practice with a telescope within the next week. This will give us more data and experience to refine the current implementation and make improvements accordingly.

It notably encompasses:

1. ZenithNeighbourhoodQuery and ZenithNeighbourhoodQueryResult, to identify an area around the zenith that is suitable for focus calibration, given the chosen focus measurement operator.
2. AnalyticResponseAutofocuser(SweepingAutofocuser), to perform an autofocusing procedure utilising the analytic nature of the focus response curve of a given focus measure, such as HFRStarFocusMeasure or GaussianStarFocusMeasure.