0.6.4

- [X] Minor change to allow abbreviated file path - https://github.com/org-trello/org-trello/pull/213
- [X] Update version
- [X] Move file list functionality to org-trello.el - CLOSE https://github.com/org-trello/org-trello/issues/214
- [X] Add ;;;### autoload for the org-trello's default commands
- [X] Release notes