Cleanup of 8bdb105897.
Add build macro to configuration header and documentation. Add
corresponding CMake option. Add change log entry and credit. Add
loader static library to link dependencies and add detection to
FindVulkan.cmake.
This allows clients to link GLFW with a staticly-built loader library.
This is useful in hermetic build systems that build the Khronos loader
from source, rather than depending on the LunarG SDK binaries.
Closes#820.
Added GLFW_INCLUDE_VULKAN. Added glfwVulkanSupported,
glfwGetRequiredInstanceExtensions, glfwGetInstanceProcAddress,
glfwGetPhysicalDevicePresentationSupport and glfwCreateWindowSurface.
Added port of LunarG SDK tri example.
