Fault correction, I'm french :(
find_visit_method_for replace by the public method visit_as
params parameter added to visit and visit_as
DesignWizard::VisitorPattern::Helper methods moved into DesignWizard::VisitorPattern
visitor_for method renamed when_visiting
params parameter of visit and visit_as methods removed
before_visiting and after_visiting implemented (not tested :s)
MethodBuilder re-added