HashCode for saving the computed images.

Still a problem : for the first computed image, we use several time the same function to computed the image (but there is only one calculation). See the print on terminal to understand.
Gitignore : ignore the backup files (json).
Merge branch 'develop' of github.com:buttleofx/ButtleOFX into develop

Conflicts:
	buttleofx/gui/viewer/qml/Player.qml