Refactor - Adapt missing information.
Refactor - Remove useless namespaces (cf. trace-function)
  - [X] Adapt cask packaging
Add a target to compile org-trello.
  - [X] Add missing standard header to namespace
  - [X] Does org-trello still compiles? NO
  - [X] Fix simple compilation warnings
  - [X] Fix some more warnings
Fix - Use car/cdr implementation instead of first/second
Refactor - Move a function to its rightful namespace
Clean - Remove dead code
Refactor - Move setup code to the setup namespace
Refactor - Add missing require statements
Refactor - Force the means to load the code from scratch.
  - [X] Does org-trello's test work? YES
  - [X] Does org-trello work? NO