* header::result is a family of functions to replace header::status
* header interface now uses status enum and also ints
* reason-phrase is no longer stored unless the user explicitly
requests it.
* When serializing, the standard reason is used for the
corresponding status code unless the user has changed it.
fix#404
Parsing and serialization interfaces have been fine tuned and unified.
For parsing these stream operations are defined:
* read
* read_header
* read_some
* async_read
* async_read_header
* async_read_some
For serialization these stream operations are defined:
* write
* write_header
* write_some
* async_write
* async_write_header
* async_write_some
fix#398
A new enum status is added for the status code.
The function obsolete_reason returns default reason phrasing.
If a response has an empty reason, the serializer will
automatically insert the default reason phrase for the
status code.
serializer interface is changed to be buffer-only, no streams,
and placed in its own header file.
Operations on serializers are moved to free functions as part
of the HTTP write family of synchronous and asynchronous algorithms.