Support the --create-dirs option

[ecampidoglio]

It would be nice if Cake.Curl exposed the --create-dirs option when downloading a file from a remote host.

From curl's documentation:

When used in conjunction with the -o, --output option, curl will create the necessary local directory hierarchy as needed. [...] If the --output file name uses no dir or if the dirs it mentions already exist, no dir will be created.

Since this option only applies to downloading a file, it would make sense to add it to the CurlDownloadSettings type.

[ecampidoglio]

Fixed in f09f146.