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

Closes #434

Examples/test-suite/python/director_pass_by_value_runme.py

@@ -0,0 +1,13 @@
+import director_pass_by_value
+
+passByVal = None
+class director_pass_by_value_Derived(director_pass_by_value.DirectorPassByValueAbstractBase):
+  def virtualMethod(self, b):
+    global passByVal
+    passByVal = b
+
+# bug was the passByVal global object was destroyed after the call to virtualMethod had finished.
+director_pass_by_value.Caller().call_virtualMethod(director_pass_by_value_Derived())
+ret = passByVal.getVal();
+if ret != 0x12345678:
+  raise RuntimeError("Bad return value, got " + hex(ret))