Will try latter to have some sort of hash map to have a separate set of
packages for different bots if needed but it's clearly not the priority
for now.

Try to get ride of global static variable, without success for now...

Note: Every ACL must be positive for the user to have access to
the package.

The &str type should be lighter than String.

/!\ For now no command is found... /!\

The permissions related to a CmdPackage can now be initialized from the
configuration file.

Add rustup instructions to install rustc and cargo