2001-05-01  Almer S. Tigelaar  <almer@gnome.org>

 	* src/parser.y (yylex): Seek for matching )'s for ('s and
 	vice versa.
 	(find_bracket): The meat for the above functionality
 	(find_char): Split out from yylex, might be useful in other
 	places. Currently used to scan for matching quotes.
	(gnumeric_expr_parser): If the ExprTree is null, assume that
	an error has occurred, set a general "invalid expression" and
	mark the whole expression. Also display more detail when both
	the expression and error message are non-null.