OS X: disable `glTexStorage2D` because of OSG/driver issue

See http://forum.openscenegraph.org/viewtopic.php?p=65276#65276 for the details.

apps/opencs/main.cpp

@@ -43,6 +43,10 @@ class Application : public QApplication
 
 int main(int argc, char *argv[])
 {
+    #ifdef Q_OS_MAC
+        setenv("OSG_GL_TEXTURE_STORAGE", "OFF", 0);
+    #endif
+
     try
     {
         // To allow background thread drawing in OSG

apps/openmw/main.cpp

@@ -321,6 +321,10 @@ private:
 
 int main(int argc, char**argv)
 {
+#if defined(__APPLE__)
+    setenv("OSG_GL_TEXTURE_STORAGE", "OFF", 0);
+#endif
+
     // Some objects used to redirect cout and cerr
     // Scope must be here, so this still works inside the catch block for logging exceptions
     std::streambuf* cout_rdbuf = std::cout.rdbuf ();