Fix Trac #3155: better error message when -XRankNTypes is omitted
This patch sligtly re-adjusts the way in which the syntax of types is handled: * In the lexer, '.' and '*' are always accepted in types (previously it was conditional). This things can't mean anything else in H98, which is the only reason for doing things conditionally in the lexer. * As a result '.' in types is never treated as an operator. Instead, lacking a 'forall' keyword, it turns into a plain parse error. * Test for -XKindSignatures in the renamer when processing a) type variable bindings b) types with sigs (ty :: kind-sig) * Make -XKindSignatures be implied by -XTypeFamilies Previously this was buried in the conditonal lexing of '*'