Aiocogeo

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- Remove unnecessary calls to the thread pool (89)
- Add header cache (90, 94)
- Renames the `ENABLE_CACHE` environment variable to `ENABLE_BLOCK_CACHE`.
- Adds the `ENABLE_HEADER_CACHE` environment variable.
- Restructure test cases (91)
- Implement chunking and smarter tag reading to reduce number of requests sent when reading the header (95)
- Adds the `HEADER_CHUNK_SIZE` environment variable (defaults to 16KB).

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- Add `CompositeReader` and `STACReader` (70)
- Align mask recognition with GDAL RFC 15 (72)
- Read color interpretation (75)
- Improve geokey parsing (79)

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- Add method to read pixel values at a given point (62)
- Add method to create downsampled version of the image (63)
- Bugfixes (60, 61)

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- Use PIL for resize instead of skimage (57)

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- Add support for nodata values (47)
- Improve filesystem exception handling (48)
- Track header size (49)
- Add support for boundless reads (51)
- Add ``BOUNDLESS_READ`` configuration option which determines if internal tiles outside bounds of the IFD are read
- Add ``BOUNDLESS_READ_FILL_VALUE`` configuration option which determines the value used to fill boundless reads
- Remove asyncio callbacks (52)
- Add support for packbits compressed images (54)

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- Runs cpu bound code in background executor (44)