Fix Ruby 1.9.2 'Encoding::UndefinedConversionError: \xA3 from ASCII-8BIT to UTF-8' in S3.to_file

lib/paperclip/storage/s3.rb

@@ -131,6 +131,7 @@ module Paperclip
         extname  = File.extname(filename)
         basename = File.basename(filename, extname)
         file = Tempfile.new([basename, extname])
+        file.binmode
         file.write(AWS::S3::S3Object.value(path(style), bucket_name))
         file.rewind
         return file