ZSNES 2.3.8

Fixes

• Fix an issue with the audio quality on macOS.

Performance improvements

• Compile with link time optimizations enabled (-flto), for some platforms.
• Build with PIE by default for several platforms, but not for 32-bit x86, for better performance.
• Add experimental support for Vulkan.
• Several performance improvements.

Experimental features

• Improve the client side of the experimental netplay support.

Various

• Add a -V / --verbose flag.
• Some refactoring.
• Update the CI configuration.
• Add more tests.
• Update documentation.