Merge pull request #290 from zigimg/migration-to-zig-0.15

Migration to zig 0.15

Merge pull request #275 from zigimg/zig-0.14

Migrate to Zig 0.14.1

Merge pull request #274 from warpdesign/tiff-iff-share-packbits-compr…

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tiff+iff: share packbits compression