Fix directorin SWIGTYPE typemaps to make a copy as these are used for pass by value.

Closes #434

Examples/test-suite/director_pass_by_value.i

@@ -0,0 +1,30 @@
+%module(directors="1") director_pass_by_value
+%director DirectorPassByValueAbstractBase;
+
+%inline %{
+class PassedByValue {
+  int val;
+public:
+  PassedByValue() { val = 0x12345678; }
+  int getVal() { return val; }
+};
+
+int doSomething(int x) {
+  int yy[256];
+  yy[0] =0x9876;
+  return yy[0];
+}
+
+class DirectorPassByValueAbstractBase {
+public:
+  virtual void virtualMethod(PassedByValue pbv) = 0;
+  virtual ~DirectorPassByValueAbstractBase () {}
+};
+
+class Caller {
+public:
+  void call_virtualMethod(DirectorPassByValueAbstractBase &f) {
+    f.virtualMethod(PassedByValue());
+  }
+};
+%}