doc: Change yat2m to allow arbitrary condition names.
* doc/yat2m.c (MAX_CONDITION_NESTING): New. (gpgone_defined): Remove. (condition_s, condition_stack, condition_stack_idx): New. (cond_is_active, cond_in_verbatim): New. (add_predefined_macro, set_macro, macro_set_p): New. (evaluate_conditions, push_condition, pop_condition): New. (parse_file): Rewrite to use the condition stack. (top_parse_file): Set prefined macros. (main): Change -D to define arbitrary macros.
This change allows the use of other conditionals than "gpgone" and
thus make "gpgtwoone" et al. actually work. It does now also track
conditionals over included files.
- Signed-off-by: Werner Koch <wk@gnupg.org>