Niondata

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- Fix display RGB calculation on integer images.
- Add methods for better control of data ref count.

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- Add setters for timezone, timezone_offset, and timestamp.

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- Add measure_relative_translation function to xdata. Utilize in align.
- Generalize align and register sequence to accept any combo of sequence and collection dimensions.
- Provide more descriptive data dimensions string.

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- Fix squeeze to not remove last datum dimension.
- Add re-dimension function (changes data description, keeps data layout in memory the same).
- Ensure that data_descriptor is a copy, not a reference, when accessed from DataAndMetadata.
- Add calibration and data_descriptor creation methods to xdata_1_0.
- Change crop to always produce the same size crop, even if out of bounds. Fill out of bounds with zero.
- Add crop_rotated to handle crop with rotation (slower).

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- Automatically promote ndarray and constants (where possible) to xdata in operations.
- Fix FFT-1D scaling and shifting inconsistency.
- Add average_region function (similar to sum_region).

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- Fix timezone bug.