file needs explicit binary mode if on Windows

[Yakumounr]

line 139 of images.py

                with open( self.imagepath(result['name']), 'w') as f:

needs to be

                with open( self.imagepath(result['name']), 'wb') as f:

on windows, or the files written will be corrupt.

same for line 172

            self.request.response.body_file = open( self.imagepath(page), 'r', 10000)

should be

            self.request.response.body_file = open( self.imagepath(page), 'rb', 10000)