Override incompatible 1.8.7p1 String#chars

activesupport/lib/active_support/core_ext/string/unicode.rb

@@ -4,6 +4,12 @@ module String #:nodoc:
       unless '1.9'.respond_to?(:force_encoding)
         # Define methods for handling unicode data.
         module Unicode
+          def self.included(base)
+            if '1.8.7'.respond_to?(:chars)
+              base.class_eval { remove_method :chars }
+            end
+          end
+
           # +chars+ is a Unicode safe proxy for string methods. It creates and returns an instance of the
           # ActiveSupport::Multibyte::Chars class which encapsulates the original string. A Unicode safe version of all
           # the String methods are defined on this proxy class. Undefined methods are forwarded to String, so all of the