Upgrade NVTT to version 2.1.1, fixes #4549.
Windows binaries built with toolset v140_xp.
Tested under Windows, Linux and macOS.
Includes a patch for building on musl Linux, contributed by voroskoi, containing code by leper.
Use the opportunity to set native line endings in the NVTT bundle.
Differential Revision: https://code.wildfiregames.com/D2475