0.1.6

- [X] Use the native org checklist to sync to trello
- [X] Sync entity and arborescence tree
- [X] Sync to trello must sync the native checklist if the flag is activated
- [X] Sync from trello must create native checklists if the flag is activated
- [X] Cleanup routine must cleanup the new checklist.
- [X] Delete entity must remove entity on point
- [X] Upgrade version
- [X] Automate the release to marmalade
- [X] Justify the #PROPERTIES# to the left for a better rendering
- [X] Keywordify the #PROPERTIES#
- [X] Merge the org :PROPERTIES: and the org-trello #PROPERTIES# into one.
- [X] Improve the activation/deactivation of the new way
- [X] Update the readme about the new checkbox mode
- [X] Release notes
- [X] Release