module to declare class attributes Moose-style

 MooseX::ClassAttribute allows you to declare class attributes in exactly the
 same way as object attributes, using class_has() instead of has().
 .
 You can use any feature of Moose's attribute declarations, including
 overriding a parent's attributes, delegation (handles), attribute traits,
 etc. All features should just work. The one exception is the "required" flag,
 which is not allowed for class attributes.
 .
 The accessor methods for class attribute may be called on the class directly,
 or on objects of that class. Passing a class attribute to the constructor
 will not set that attribute.