Generate Xcode project files.

This supports Xcode 3.0 and above. Support for Xcode versions prior to Xcode 5 is deprecated and will be dropped in a future version of CMake.

Toolset Selection

By default Xcode is allowed to select its own default toolchain. The CMAKE_GENERATOR_TOOLSET option may be set, perhaps via the cmake(1) -T option, to specify another toolset.