fix printing precedence for BETWEEN, LIKE/ESCAPE, REGEXP, IN
don't use precedence for printing CASE/WHEN/THEN/ELSE/END

fix parsing precedence of BETWEEN, LIKE/ESCAPE, REGEXP, IN
support predicate arguments for IN, BETWEEN, SOUNDS LIKE, LIKE/ESCAPE,
REGEXP

use %nonassoc for unary operators

fix parsing of IS TRUE/FALSE/UNKNOWN/NULL

remove parser_precedence test as superseded by the precedence test