• use sync.Map or mutex to make encoder/decoder cache thread safe
• fix #198 use vendoring
• fix #200 removed symbolic link
• fix #202 crash on custom map encoder
• fix #207 Encoding nil pointer to struct containing exported function leads to marshalling error
• fix #214 do not wrap EOF
• fix #217 when input is "null", should not report error for unmarshallable type
• fix #219 nested field with json tag 'omitempty' should not be marshalled if it has zero value
• fix #227 incorrect marshalling of json.Number for empty string
• fix #228 Any.ToInt() resulting not nil LastError()