Fixed software renderer being selected on OS X.

README.md

@@ -108,6 +108,8 @@ GLFW bundles a number of dependencies in the `deps/` directory.
  - [Cocoa] Bugfix: Joystick enumeration took hundreds of ms on some systems
  - [Cocoa] Bugfix: The cursor was hidden when the user resized a GLFW window
  - [Cocoa] Bugfix: The 10.10 Yosemite OpenGL 4.1 profile token was not used
+ - [Cocoa] Bugfix: The generic software OpenGL renderer could be selected under
+                   certain conditions
  - [Win32] Enabled generation of pkg-config file for MinGW
  - [Win32] Removed option to require explicitly linking against `winmm.dll`
  - [Win32] Bugfix: Failure to load winmm or its functions was not reported to

src/nsgl_context.m

@@ -124,6 +124,7 @@ int _glfwCreateContext(_GLFWwindow* window,
     // Arbitrary array size here
     NSOpenGLPixelFormatAttribute attributes[40];
 
+    ADD_ATTR(NSOpenGLPFAAccelerated);
     ADD_ATTR(NSOpenGLPFAClosestPolicy);
 
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= 1070