binmode and Tempfile fixes for windows

lib/paperclip/attachment.rb

@@ -67,6 +67,7 @@ module Paperclip
       return nil unless valid_assignment?(uploaded_file)
       logger.info("[paperclip] Assigning #{uploaded_file.inspect} to #{name}")
 
+      uploaded_file.binmode if uploaded_file.respond_to? :binmode
       queue_existing_for_delete
       @errors            = []
       @validation_errors = nil

lib/paperclip/iostream.rb

@@ -41,3 +41,18 @@ end
     end
   end
 end
+
+# Corrects a bug in Windows when asking for Tempfile size.
+if defined? Tempfile
+  class Tempfile
+    def size
+      if @tmpfile
+        @tmpfile.fsync
+        @tmpfile.flush
+        @tmpfile.stat.size
+      else
+        0
+      end
+    end
+  end
+end