simple class variable accessors

 Class::Accessor::Class provides a simple way
 to create accessor and mutator methods for class variables,
 just as Class::Accessor provides for objects.
 It can use either an enclosed lexical variable,
 or a package variable.
 .
 This module was once implemented in terms of Class::Accessor,
 but changes to that module broke this relationship.
 Class::Accessor::Class is still a subclass of Class::Accessor,
 strictly for historical reasons.
 As a side benefit,
 a class that isa Class::Accessor::Class is also a Class::Accessor
 and can use its methods.
 .
 NB! This module is deprecated upstream.