Restore --no-lines.

Reported by Jim Kent.
* data/c.m4 (b4_syncline): New.
* data/glr.c, data/yacc.c, data/lalr1.cc: Use it.
* src/reader.c (prologue_augment, epilogue_set): Use b4_syncline.
* src/output.c (user_actions_output): Likewise.
(prepare): Define 'b4_synclines_flag'.

TODO

@@ -155,21 +155,11 @@ Paul notes:
 Show reductions.	[]
 
 * Broken options ?
-** %no-lines		[ok]
 ** %no-parser		[]
-** %pure-parser		[]
 ** %token-table		[]
-** Options which could use parse_dquoted_param ().
-Maybe transferred in lex.c.
-*** %skeleton		[ok]
-*** %output		[]
-*** %file-prefix	[]
-*** %name-prefix	[]
-
 ** Skeleton strategy.	[]
 Must we keep %no-parser?
 	     %token-table?
-*** New skeletons.	[]
 
 * src/print_graph.c
 Find the best graph parameters.	[]