Remote images stored in root of files directory - add config to provide further storage options

Rather than adhering to the rules set out for uploaded images, any image added via Media from a remote source is stored in files/public/ which is gonna get pretty untidy pretty fast. It would be great if we could have so control over where these files get stored (if it could work with fe_paths that would be really handy).

In the meantime, https://drupal.org/project/remote_stream_wrapper provides a possible solution but only if you're not intending to use image styles.