Patch release with a change to default zip compression level:
- Default zip compression level is now 4 (instead of 6), which in our tests improves compression times by 2x with only a tiny drop in compression ratio.
- setDefaultZipCompression() and setDefaultDwaCompression() now set default compression levels for writing.
- The Header now has zipCompressionLevel() and dwaCompressionLevel() to get/set the levels used for writing.
Also, various bug fixes, build improvements, and documentation updates. In particular:
- Fixes a build failure with Imath prior to v3.1
- Fixes a bug in detecting invalid chromaticity values