b4_tables_map.

b4_tables_map.

The point is to factor the generation of the tables across skeletons.
This is language dependant.

	* data/c.m4 (b4_comment_): New.
	Should be usable to define how to generate tables independently of
	the language.
	(b4_c_comment): New.
	(b4_comment): Bounce to b4_c_comment.
	Now support $2 = [PREFIX] for indentation.
	* data/lalr1.cc (b4_table_declare): Don't output a comment if
	there is no comment.
	Indent it properly when there is one.
	Output the ending semicolon.
	(b4_table_define): Space changes.
	Output the ending semicolon.
	(b4_tables_map): New.
	Use it twice instead of declaring and defining the (integral)
	tables by hand.