** DONE filter out level > 4 when syncing.
CLOSED: [2013-07-07 dim. 23:03]
** DONE Given a trello board, sync into a org-mode file

- correctness first, display the cards as org-mode file

- add their status depending on their list (todo, doing, done)

- add the orgtrello-id properties (for further sync)

- unify the use of the *ORGTRELLO-ID* aka "orgtrello-id" on org-trello.el

- Write the full board inside the org-mode file
TODO v0.0.4 + Update README.md