remove maildir-log call, doesn't seem useful anyway
switch from a complex loop to dash functions
maildir/complete-folder - allow car or cde of the alist to be selected
maildir/folder-home: like maildir/home but for folders
maildir-list: complex prefix-arg handling to open other dirs as maildirs
maildir-transfer-folder: new function to copy files from the cache of one maildir to another
better help for maildir-transfer-folder