Fix version related descriptions.
Fix Unpacker.ReadString/ReadBinary of subtree unpacker leads to subsequent unpacking failure when unpacked value is nil or empty [issue #10].

Signed-off-by: yfakariya <yfakariya@gmail.com>
Fix blank lines.
Fix SerializerGenerator only supports standalone object.
Fix merge error.
Exclude SerializerGenreatorTest from WinRT.
Fix warning.
Add Contains()  for internal use.
Improve test methods.
Add multiple type support.
Code cleanup.
Add IUnpackable tests.
Fix spec URL.