Fixed last use of wndconfig in EGL port.
Added GLFW_INCLUDE_ES31.

Fixes #255.
Reverted 43095307da327e82f136c5fe17d4fdecb3f78cb6.

The proposed fix broke for multiple displays of the same model.
Fixed bad change log edit.
Added support for custom system cursors.

This adds 3 functions to the GLFW API: glfwCreateCursor,
glfwDestroyCursor and glfwSetCursor.
Cleanup.
Added GLFWimage struct.
Formatting.
Updated change log.
First draft of physical key fix for Windows.
Updated change log.
Added custom cursors to news.