Protocol_Error is common for the whole library.
Black.Text_IO: Expand the number of types, which can be written to a stream in textual form.
Moving the HTTP status lines to package Black.HTTP.  Special types for header keys and websocket accept keys.
Black.Parsing: Internal parsing routines.
Black: White-space fix.
Black.Response: Turned the response data structure into a regular variant record.  Introducing Input_HTTP (matching Output_HTTP).
Black.Request: Using the new, common parsing routines.
Tests: New order of header fields.