* cpplib.c (end_directive): Handle line skipping. Only remove
the rest of the line if the directive was valid.
* cppmacro.c (_cpp_push_text_context): Set NODE_DISABLED when
expanding a traditional macro.
* cpptrad.c (recursive_macro): New.
(read_logical_line_trad): Handle skipping.
(scan_out_logical_line): Continue after a successful directive.
Don't expand macros whilst skipping, or if recursing.
(_cpp_create_trad_definition): scan_out_logical_line now sets
the output current position.