Partial rewriting and single file executable

[IGLOU-EU]

Hi,

The purpose of this PR:

• Allow to invoke args in disorder
• Fix check that was not executed
• Add an HELP and MOTD
• Add logger messages and colors
• Do not use colors if not available
• Add initialization part
• Split the script in several subparts
• Keep a main script for development
• Add a constructor to have a single autonomous executable

I know it's a big PR, and it would have been nice to cut it. My bad :S
PS: I'm sorry Kevin, I can't remember what I had planned at the beginning, so ... I made this 😅

[IGLOU-EU]

Ok, I probably miss some stuff... but globally, that done.
We just need to run ./utils/builder.sh to make a release.