Emulate Class::Accessor::Fast behavior using Moose attributes

This module attempts to emulate the behavior of Class::Accessor::Fast
as accurately as possible using the Moose attribute system. The public
API of "Class::Accessor::Fast" is wholly supported, but the private
methods are not. If you are only using the public methods (as you
should) migration should be a matter of switching your "use base" line
to a "with" line.