Now that qbool is fixed, let's fix getting and setting a bool
value to a qdict member to also use C99 bool rather than int.

I audited all callers to ensure that the changed return type
will not cause any changed semantics.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>