Removed all references to using namespace std to help solve compilation problems

under Windows and IRIX.

Also integrated small change to lib3ds from Drew for IRIX compilation.

src/osgPlugins/flt/Input.cpp

@@ -10,20 +10,8 @@
 #include "Record.h"
 #include "Registry.h"
 
-#ifdef __sgi
-using std::string;
-#endif
-
-#ifdef OSG_USE_IO_DOT_H
-#include <iostream.h>
-#else
-#include <iostream>
-using namespace std;
-#endif
-
 using namespace flt;
 
-
 FileInput::FileInput()
 {
     _init();