Refactor - Move buffer function to buffer namespace
Refactor - Move set property function to buffer namespace
  - [X] Sanitize functions (move functions to their right namespaces)
- [X] Provide org-trello-mode-hook - CLOSE https://github.com/org-trello/org-trello/issues/116
  - [X] Do not override the user's existing tags
- [X] Open stop all synchronization actions - CLOSE https://github.com/org-trello/org-trello/issues/131
Refactor - rename orgtrello-elnode/remove-file to orgtrello-action/delete-file!
Refactor common behavior to delete one entity action file
Refactor - add the log message when org-trello namespace is loaded.
Fix test log message
  - [X] sync-buffer, sync-to-trello, with C-u, sync-from-trello
Refactor - extract common behavior
Refactor - extract common behavior
Refactor - extract common behavior
Format
Fix test log message
Synchronize help message
Add utility function to help in determining region zone for the
different entities
Fix typo
Refactor - rename function