Added separate platform headers for EGL and GLX.

src/cocoa_platform.h

@@ -41,6 +41,10 @@
 typedef void* id;
 #endif
 
+// This path may need to be changed if you build GLFW using your own setup
+// We ship and use our own copy of glext.h since GLFW uses fairly new
+// extensions and not all operating systems come with an up-to-date version
+#include "../support/GL/glext.h"
 
 #define _GLFW_PLATFORM_WINDOW_STATE  _GLFWwindowNS NS
 #define _GLFW_PLATFORM_CONTEXT_STATE _GLFWcontextNSGL NSGL