Add patch for qt build with MacOS "El Capitan" SDKs (happen with all Xcode 7+)

Projects/patches/qt.elcapitan-macossdk.patch

+From 27aa46933bb32a88c310fe5918a49a3f34d65dfe Mon Sep 17 00:00:00 2001
+From: Mike McQuaid <mike@mikemcquaid.com>
+Date: Sun, 13 Sep 2015 11:55:59 +0100
+Subject: [PATCH] Fix El Capitan build.
+
+---
+ src/gui/painting/qpaintengine_mac.cpp | 8 +-------
+ 1 file changed, 1 insertion(+), 7 deletions(-)
+
+diff --git a/src/gui/painting/qpaintengine_mac.cpp b/src/gui/painting/qpaintengine_mac.cpp
+index 4aa0668..63b646d 100644
+--- a/src/gui/painting/qpaintengine_mac.cpp
++++ b/src/gui/painting/qpaintengine_mac.cpp
+@@ -340,13 +340,7 @@ CGColorSpaceRef QCoreGraphicsPaintEngine::macDisplayColorSpace(const QWidget *wi
+     }
+ 
+     // Get the color space from the display profile.
+-    CGColorSpaceRef colorSpace = 0;
+-    CMProfileRef displayProfile = 0;
+-    CMError err = CMGetProfileByAVID((CMDisplayIDType)displayID, &displayProfile);
+-    if (err == noErr) {
+-        colorSpace = CGColorSpaceCreateWithPlatformColorSpace(displayProfile);
+-        CMCloseProfile(displayProfile);
+-    }
++    CGColorSpaceRef colorSpace = CGDisplayCopyColorSpace(displayID);
+ 
+     // Fallback: use generic DeviceRGB
+     if (colorSpace == 0)
+-- 
+2.3.8 (Apple Git-58)
+

Projects/qt.cmake

@@ -26,6 +26,11 @@ elseif (APPLE)
   #find . -name "*.pro" -exec sed -i -e "s:/Developer/SDKs/:.*:g" {} \;
   set (patch_command
        PATCH_COMMAND /usr/bin/find . -name "*.pro" -exec sed -i -e "s:/Developer/SDKs/:.*:g" {} +)
+  add_external_project_step(qt-patch-osx
+    COMMAND git apply --whitespace=fix ${SuperBuild_PROJECTS_DIR}/patches/qt.elcapitan-macossdk.patch
+    WORKING_DIRECTORY <SOURCE_DIR>
+    DEPENDEES patch
+    DEPENDERS configure)
 endif()
 set(qt_EXTRA_CONFIGURATION_OPTIONS ""
     CACHE STRING "Extra arguments to be passed to Qt when configuring.")