Re-create courierimapsubscribed with all folders subscribed

If you have a lot of folders in your IMAP mailbox, it can be pain to subscribe to all of them by hand. With courier-imap, the subscribed folders lists is one-entry-per-line list of directories in your mailbox. To subscribe to all folders, run the following in your root maildir:

$ find -type d -name ".*"  | tail -n+2 | sed 's/\.\/\./INBOX\./g' > courierimapsubscribed