COMP: Fix compilation failures with GCC 4.7.

It seems that intptr_t has moved into stdint.h.

Change-Id: I1a1d2cfb4b9bff3033b73d202faf801285bdeba5

Rendering/vtkFreeTypeTools.cxx

@@ -31,6 +31,8 @@
 // The embedded fonts
 #include "fonts/vtkEmbeddedFonts.h"
 
+#include <stdint.h>
+
 #ifdef FTGL_USE_NAMESPACE
 using namespace ftgl;
 #endif

Rendering/vtkFreeTypeUtilities.cxx

@@ -31,6 +31,7 @@
 #include "fonts/vtkEmbeddedFonts.h"
 
 #include <sys/stat.h>
+#include <stdint.h>
 
 #ifdef FTGL_USE_NAMESPACE
 using namespace ftgl;