Extensions represents the valid list of extensions to upload.

NewFsUploadable returns a newly instantiated FsUploadable instance.

NewFsUploadables returns a new instance of an Uploadables which creates Uploadable instances from files on the filesystem.

Replace will update the Uploadable's URI if the image was already uploaded If `update` is false the URI will not be updated.

Skip checks if the Uploadable is already uploaded by comparing MD5s If `force` is true the Uploadable will be always be uploaded.

ErrSkip is used to skip an Uploadable.

FsUploadable creates Uploadable instances.

PreFunc is called before the file is opened.

UseFunc is called after the file is opened but before being uploaded.