Erik Hofman

isWater, isSea and getIndex are now const and use find(), so they never insert into the shared map. An unknown landclass is not water, not sea, and has index 0, which matches what operator[] returned before. Also added is hasLandclass(int), which lets the C++ side tell a missing landclass apart from index 0

Make the ShaderVG code more robust.

Support the TZif v2+ second data block which upgrades time values from 32-bit to 64-bit (8-byte) signed integers and all multi-byte integers are stored in network byte order (big-endian) using two's complement.

Cloud generation crashes on addCloudToDetailedVoxelField when the file is not available

Turn the _scissor raw-pointer into an osg::ref_ptr<RelativeScissor>. This fixes #3360

git-clang-format

Merge branch 'next' into aisim

Clean up the code and add a number of clarification comments.