Added GLFW_INCLUDE_ES31.

Fixes #255.

README.md

@@ -47,12 +47,13 @@ The following dependencies are needed by the examples and test programs:
 
  - Added native monitor handle access to native API
  - Added `glfwSetDropCallback` and `GLFWdropfun` for receiving dropped files
+ - Added `glfwPostEmptyEvent` for allowing secondary threads to cause
  - Added `empty` test program for verifying posting of empty events
+ - Added `GLFW_INCLUDE_ES31` for including the OpenGL ES 3.1 header
  - Bugfix: The debug context attribute was set from `GL_ARB_debug_output` even
            when a debug context had not been requested
  - Bugfix: The particles example was not linked against the threading library
- - Added `glfwPostEmptyEvent` for allowing secondary threads to cause
-   `glfwWaitEvents` to return
+           `glfwWaitEvents` to return
  - [Cocoa] Added `_GLFW_USE_RETINA` to control whether windows will use the full
            resolution on Retina displays
  - [Cocoa] Bugfix: Using a 1x1 cursor for hidden mode caused some screen

include/GLFW/glfw3.h

@@ -158,6 +158,8 @@ extern "C" {
     #include <GLES2/gl2.h>
   #elif defined(GLFW_INCLUDE_ES3)
     #include <GLES3/gl3.h>
+  #elif defined(GLFW_INCLUDE_ES31)
+    #include <GLES3/gl31.h>
   #elif !defined(GLFW_INCLUDE_NONE)
     #include <GL/gl.h>
   #endif