Merge pull request #26 from JaderDias/master

Reenabled CSV export, rewritten to work with the new Rdio API
adjust variable names and for loop
Add getTracks method that lazy loads in the Playlist children and then executes the callback function passing the tracks through.
Fixes #24

Modified deduplcation to use the lazy load tracks.
Fixes #25

Changed all the sort playlists function to pass keys because of an API change.
update readme for 2.7 release
Releasing version 2.7
added Export to CSV button to collection, for now it shows the wrong icon and it only downloads the visible tracks