Fix directory naming

The "test" directory was renamed to "tests" in all projects.
joy-frontend: Add FreeType and FreeImage support
build system: Reduce verbosity
build system: Improve support for FreeImage
build system: Improve support for FreeType
joy-frontend: Improve build system
build system: Fix FreeImage support on Linux
toolbox: Clean up
lip: Clean up
lcc: Clean up
joy-frontend: Improve joy-frontend
toolbox: Fix file and function naming issues
joy-frontend: Improve joy-frontend
joy-frontend: Add check
toolbox: Add mutex
toolbox: Improve doc comments
toolbox: Improve consistency
toolbox: Add string iterator
build system: Improve build system