(rescan, handle_directive): Backslash no longer suppresses the specialness of the following char unless -traditional.

(rescan, handle_directive): Backslash no longer suppresses the specialness of
the following char unless -traditional.
(rescan): Remove backslash-newline only if at top level, since
backslash-newline-space can be encountered during macro processing.
(collect_expansion): Remove special hack for \# inside a #define; it's not
compatible with the C Standard.

From-SVN: r8069