Add filter for get_attached_file() - use S3 URL by default but ability to copy back the file to be used by certain processes
Allow the Regenerate Thumbnails plugin to copy back file to server for processing
Merge branch 'develop' into get-attached-file-support
Return URL earlier if issues with filesystem API
Merge pull request #170 from deliciousbrains/get-attached-file-support

Support for get_attached_file()