Cgohlke

- Add LZF codec via liblzf.

- Read Olympus SIS (WIP).
- Allow to write non-BigTIFF files up to ~4 GB (fix).
- Fix parsing date and time fields in SEM metadata.
- Detect some circular IFD references.
- Enable WebP codecs via imagecodecs.
- Add option to read TiffSequence from ZIP containers.
- Remove TiffFile.isnative.
- Move TIFF struct format constants out of TiffFile namespace.

- Use str, not bytes for ASCII data.

- Fix wrong TiffTag.valueoffset.
- Towards reading Hamamatsu NDPI (WIP).
- Enable PackBits compression of byte and bool arrays.
- Fix parsing NULL terminated CZ_SEM strings.

- Move module into sdtfile package.

- Move tifffile.py and related modules into tiffile package.
- Move usage examples to module docstring.
- Enable multi-threading for compressed tiles and pages by default.
- Add option to concurrently decode image tiles using threads.
- Do not skip empty tiles (fix).
- Read JPEG and J2K compressed strips and tiles.
- Allow floating-point predictor on write.
- Add option to specify subfiletype on write.
- Depend on imagecodecs package instead of _tifffile, lzma, etc modules.
- Remove reverse_bitorder, unpack_ints, and decode functions.
- Use pytest instead of unittest.