All options no longer require a short name.
-> rare options are only long now.

Some options have been renamed to sound clearer.
--mmax, --mmax-workload, --enable-sg-process-tracing,
--allow-time-sharing, --workflow-jobs-limit, ...

Some default values have been changed for consistency.
--mmax and --workflow-jobs-limit both have 0 as
default unlimited value.

Running batsim --help should now be more readable, and
display what can be done via the CLI.

The problem is probably related to some IO buffering issue.
Batsim is now run in quiet mode in the tests, which hides the problem :(

Pybatsim should now be able to handle the new job_identifier syntax WLOAD!ID.

Batsim now stores the number of simulated machines into Redis.
Since the scheduler does not need to read the workload file anymore,
this argument has been removed from pybatsim's launcher.py.

Many instances can be executed thanks to Execo.
Instances already done in the past will not be recomputed :).

Variables can now be either:
  - simple. one value, accessed via ${VAR}
  - lists. accessed via @n{VAR}, where n is
    the element to access.

Remote execution is implemented but has not been tested yet.

TODO: pre and post commands of the exec1 instance
TODO: pre and post commands of the execN instances
TODO: hide error messages in the execN script?