New Features
HTTP
Add HTTP.ContentType.formData to support file upload.
Add HTTP.ContentType.octetStream to support file download.
Rename
HTTP
HTTP.HTTPContentType rename to HTTP.ContentType
HTTP.HTTPHeaderFields rename to HTTP.HeaderFields
HTTP.HTTPMethod rename to HTTP.Method
HTTP.HTTPStatus rename to HTTP.StatusCode
JSON
JSONEncodeError.dictToDataFailed rename to JSONEncodeError.encodingToJSONFailed
Remove
Remove all deprecated initializer、methods