* cppinit.c (cpp_handle_option): help_only is now part of the
        cpp_options structure.
        * cpplib.c (cpp_errors, cpp_get_options, cpp_get_callbacks,
        cpp_set_callbacks): New functions.
        * cpplib.h (cpp_callbacks): Break out as a named structure.
        (cpp_options): Move help_only here from cpp_reader.
        (CPP_FATAL_ERRORS): Update to use cpp_errors.
        (cpp_errors, cpp_get_options, cpp_get_callbacks,
        cpp_set_callbacks): New prototypes.
        * cppmain.c (main): Update for help_only.

From-SVN: r38971