fixes issue where attachment styles are losing format options when rails class caching is turned on

lib/paperclip/attachment.rb

@@ -57,7 +57,7 @@ module Paperclip
       unless @normalized_styles
         @normalized_styles = {}
         (@styles.respond_to?(:call) ? @styles.call(self) : @styles).each do |name, args|
-          @normalized_styles[name] = Paperclip::Style.new(name, args, self)
+          @normalized_styles[name] = Paperclip::Style.new(name, args.dup, self)
         end
       end
       @normalized_styles

test/attachment_test.rb

@@ -340,7 +340,7 @@ class AttachmentTest < Test::Unit::TestCase
 
   context "An attachment with styles but no processors defined" do
     setup do
-      rebuild_model :processors => [], :styles => {:something => 1}
+      rebuild_model :processors => [], :styles => {:something => '1'}
       @dummy = Dummy.new
       @file = StringIO.new("...")
     end