Fixed #204, #202.

enum support had been incomplete.
This fix made enum support complete.

Replaced int with auto on c++11 scoped enum.
Replaced template specializations with function overloads on operator<< and operator>> for enum.

enum can convert to object with and without zone.

When you want to adapt enum, you need to write as follows:

// NOT msgpack.hpp

enum yourenum {
    elem
};

MSGPACK_ADD_ENUM(yourenum);

// msgpack.hpp should be included after MSGPACK_ADD_ENUM(...)

int main() {
    msgpack::object obj(yourenum::elem);
}

test/msgpack_cpp11.cpp

@@ -1,4 +1,4 @@
-#include "msgpack.hpp"
+#include <msgpack_fwd.hpp>
 
 #include <gtest/gtest.h>
 
@@ -6,12 +6,36 @@
 #include "config.h"
 #endif
 
+#if !defined(MSGPACK_USE_CPP03)
+
+class TestEnumClassMemberClass
+{
+public:
+    TestEnumClassMemberClass()
+        : t1(TestEnumClassType::STATE_A), t2(TestEnumClassType::STATE_B), t3(TestEnumClassType::STATE_C) {}
+
+    enum class TestEnumClassType:long {
+        STATE_INVALID = 0,
+            STATE_A = 1,
+            STATE_B = 2,
+            STATE_C = 3
+        };
+    TestEnumClassType t1;
+    TestEnumClassType t2;
+    TestEnumClassType t3;
+
+    MSGPACK_DEFINE(t1, t2, t3);
+};
+
+MSGPACK_ADD_ENUM(TestEnumClassMemberClass::TestEnumClassType);
+
+#include <msgpack.hpp>
+
 using namespace std;
 
 const unsigned int kLoop = 10000;
 const unsigned int kElements = 100;
 
-#if !defined(MSGPACK_USE_CPP03)
 
 // C++11
 
@@ -150,29 +174,6 @@ TEST(MSGPACK_STL, simple_buffer_unordered_multiset)
   }
 }
 
-
-
-class TestEnumClassMemberClass
-{
-public:
-    TestEnumClassMemberClass()
-        : t1(TestEnumClassType::STATE_A), t2(TestEnumClassType::STATE_B), t3(TestEnumClassType::STATE_C) {}
-
-    enum class TestEnumClassType:long {
-        STATE_INVALID = 0,
-            STATE_A = 1,
-            STATE_B = 2,
-            STATE_C = 3
-        };
-    TestEnumClassType t1;
-    TestEnumClassType t2;
-    TestEnumClassType t3;
-
-    MSGPACK_DEFINE(t1, t2, t3);
-};
-
-MSGPACK_ADD_ENUM(TestEnumClassMemberClass::TestEnumClassType);
-
 TEST(MSGPACK_USER_DEFINED, simple_buffer_enum_class_member)
 {
     TestEnumClassMemberClass val1;