Added API versioning.
Added a minimal forward declaration header file for pack/unpack overloading.
Removed wrong tr1:: from unordered containers.
Moved include byteswap.h to sysdep.h.
When compiling on Mac, byteswap.h is not included.
Separated adaptor functions' definitions and declarations.
Added packer_serializer class template declaration to object_fwd.hpp
Replaced tuple with std::tuple.
Added include file int_fwd.hpp for MSGPACK_ADD_ENUM.
Merge pull request #137 from redboltz/remove_tr1_from_test

Removed wrong tr1:: from unordered containers.
Merge pull request #138 from redboltz/move_byteswap

Moved include byteswap.h to sysdep.h.
Minimized header files dependency.
Added help comments for typical compile error.
Fixed https://github.com/msgpack/msgpack-c/pull/95 on poc/0.6 branch.
Merge pull request #140 from redboltz/fix_issue95_on_poc0.6

Fixed https://github.com/msgpack/msgpack-c/pull/95 on poc/0.6 branch.
Added a 32bit environment tests for travis-ci.
Merge pull request #141 from redboltz/add_32bit_test_for_travisci

Added a 32bit environment tests for travis-ci.
Merge branch 'api_versioning' of https://github.com/redboltz/msgpack-c into redboltz-api_versioning

Conflicts:
	include/msgpack/unpack.hpp
Merge branch 'redboltz-api_versioning' into poc/0.6