API Changes:
The error code enum `invalid_code_lenths` was a synonym of `invalid_code_lengths`.
Affected programs should be modified to use `invalid_code_lengths`.
refs #1934
API Changes:
The macro BOOST_BEAST_NO_DEPRECATED will no longer be noticed by Beast. The only way to
enable deprecated functionality is now the macro BOOST_BEAST_ALLOW_DEPRECATED which is
undefined by default. That is, all deprecated behaviour is disabled by default.
refs #1934
* `basic_parser` now uses pure virtual member functions instead
of the curiously recurring template pattern.
Actions Required:
* Change uses of the `basic_parser` type to omit the `Derived`
template parameter
* Classes derived from `basic_parser` no longer need to friend
the base.
* Virtual functions in the derived class may be marked `override`.
