Refactor the -Wdev and -Wno-dev to use a generic -W parser that follows
the GCC pattern. Include support for setting CMAKE_ERROR_DEPRECATED and
CMAKE_WARN_DEPRECATED via the deprecated warning. Add -Werror=dev and
-Wno-error=dev options so that dev warning options are in line with
deprecated warning options. Use a new CMAKE_SUPPRESS_DEVELOPER_ERRORS
internal cache entry to store the above new dev options persistently.
Add tests for new options and updated cmake documentation and release
notes to list new options.
Always show the option with its argument separate in summary text.
State in the main documentation that the option and its argument can be
given together too.
Define the 'cmake -A' option to set CMAKE_GENERATOR_PLATFORM
without having to spell out the whole variable name. We choose
the name '-A' for "platform" because '-P' is already taken, and
in the common use case the "platform" is actually an architecture
(e.g. x64).
Teach the RunCMake test infrastructure to use -A to pass the generator
platform. Extend the RunCMake.GeneratorPlatform test with a case to
verify that the -A option cannot be repeated.