Revue des commentaires et nommages dans unpack de sorte à ce que ce soit très clair
Added fisrt version of pack, but it wanted to be rework for optimisation.
Fix compression "value" from `0x3FF` to `0x7FF`. Now the file compress correctly. Add bytes_align function that adds missing 0x00 bytes at the end of the file. Minor variables rename to make them more explicit.