Fixed zone allocating functions always throw std::bad_alloc() if allocation is failed.
Added EXT support.
Removed obsolete unpack functions.
Updated examples that no longer use obsolete functions.
Added reference checking function to unpacked. ( unpacked::referenced() )
Added std:: namespace.
Added reference or copy choice function and default behavior:
  When you use unpacker, default behavior is:
    STR, BIN, EXT types are always held by reference.
  When you don't use unpacker, default behavior is:
    STR, BIN, EXT types are always held by copy.
    The memory is allocated from zone.
  You can customize the behavior passing your custom judging function to unpack() or unpacker's constructor.
Replaced switch-case and bit calculation with a table.
Reordered unpack selector sequence.
Removed redundant memory allocation from zone.
Removed zone::create and zone::destroy.
We can use zone as follows:
   zone z; // on stack
   zone* z = new zone; // on heap

Fixed a resource leak when zone::push_finalizer(msgpack::unique_ptr<T>) is called.
Fixed the problem that reference function doesn't pass correctly.
Fixed referenced flag writing timing on next(). It should place before flush.
Added msgpack_tuple test for CMakeLists.txt
Untabified CMakeLists.txt
Added reference function test.