It assures that we can use the same interfaces as the original version(0.5.6).
To support both C++03 and C++11, I introduced msgpack::unique_ptr and msgpack::move() in test codes.
When the compiler configured to support C++11 (e.g. CXXFLAG contains -std=c++11 is given),
those files are used.
Decoupled unpacker and msgpack_unpacker.
This modification introduced C++11 dependency such as nullptr and unique_ptr.
I will support C++11 and C++03, finally.
Decoupled msgpack.hpp and msgpack.h.
Decoupled sbuffer from msgpack_sbuffer.
Decoupled vrefbuffer from msgpack_vrefbuffer.
Decoupled zbuffer from msgpack_zbuffer.
Added some z_stream initialization.
Removed unpack macros.
Removed CTX_CAST and CTX_REFERENCED.
Embed ctx_ as a member variable (not a pointer).
Modified zone free using C++ way.
