Visual Studio 12 2013

Removed. This once generated Visual Studio 12 2013 project files, but the generator has been removed since CMake 3.31. It is still possible to build with the VS 12 2013 toolset by also installing VS 2015 (or above) and using the Visual Studio 14 2015 (or above) generator with CMAKE_GENERATOR_TOOLSET set to v120, or by using the NMake Makefiles generator.