Implement automatic LOD generation
- Added DownSampleAndCopyRegion() function that is going to be used for LOD generation.
- Fix spelling of sse2neon target in CMakeLists, add sse2neon to .gitignore.
- Allow remapping between different LODs and call DownSampleAndCopyRegion instead of DispatchBlockCopy from VolumeDataRequestProcessor::RequestRemap() in case of LOD generation.
- Fix size[1] being passed instead of size[2] and wrong determination of lastValid[XYZ].
- Added GenerateLOD test to check that LOD generation works as expected.
- Added code to create and keep track of parent VolumeDataPageAccessors/VolumeDataPages to automatically update LODs (VolumeDataPage::WriteIntoLOD doesn't do anything yet).
- Move BlockCopy/FixupBorder/DownSampleAndCopyRegion functions from VolumeDataRequestProcessor.cpp to DataBlock.cpp/DataBlock.h.
- Use only the global VolumeDataFormat/VolumeDataComponents enums in DataBlock to remove dependency on VolumeDataChannelDescriptor.
- Implemented WriteIntoLOD method for VolumeDataPage.
- Do not generate missing data errors from sparse VDSs.
- Add separate test for automatically creating LODs.
- Make parent page dirty and update hash in WriteIntoLOD().
- Update SEGYImport with options to control LOD generation.
- Use int64_t for chunk indices.