Fix subtle design flaw which caused init()

Wrapping the 'class.new()' method like in normal classes causes init
function of any created class (= instanciated object of type class) to
be executed at class creation time. This is due to the fact that the
new instanciated class object clearly contains an init function.

Considering the increasingly abstruse API it should be considered
whether to abandon the 'new()' and possibly the 'init()' function from
the class definition altogether.
Fix action labels for luks devices