Added include<string.h> to fix compile errors under gcc 4.3

src/osg/DisplaySettings.cpp

@@ -17,6 +17,7 @@
 #include <osg/ref_ptr>
 
 #include <algorithm>
+#include <string.h>
 
 using namespace osg;
 using namespace std;

src/osg/Image.cpp

@@ -24,6 +24,8 @@
 #include <osg/Texture3D>
 #include <osg/Texture2DArray>
 
+#include <string.h>
+
 #include "dxtctool.h"
 
 using namespace osg;