Adding supported types to cloudinary images.

Similar to #109, add ability to upload all supported formats for Cloudinary.

List taken from http://support.cloudinary.com/entries/23462458-What-type-of-image-formats-do-you-support- 

Some contention around the correct mime type for a PSD format. Some list it as `image/vnd.adobe.photoshop` others as `application/octet-stream`. I went with the former as I didn't want to use the latter. But I am not using PSD format files so this is not an issue for me but may be for others.