Add "unicode_strings" test case for new Python 3 behavior

Examples/test-suite/common.mk

@@ -473,6 +473,7 @@ CPP_TEST_CASES += \
 	typemap_various \
 	typename \
 	types_directive \
+	unicode_strings \
 	union_scope \
 	using1 \
 	using2 \

Examples/test-suite/python/unicode_strings_runme.py

@@ -0,0 +1,4 @@
+import unicode_strings
+
+unicode_strings.test_c_str()
+unicode_strings.test_std_string()

Examples/test-suite/unicode_strings.i

@@ -0,0 +1,15 @@
+%module unicode_strings
+
+%include <std_string.i>
+
+%inline %{
+
+const char* test_c_str(void) {
+        return "h\xe9llo";
+}
+
+std::string test_std_string(void) {
+        return std::string("h\xe9llo");
+}
+
+%}