MadGraph5_aMC@NLO 2.4.x "reweighting"

2.4.0 (12/06/16)
        OM: Allowing the proper NLO reweighting for NLO sample
        RF: For NLO processes allow for multiple PDF and scales reweighting, directy by inputting lists
            in the run_card.dat.
        VH: Interfaced MadLoop to Samurai and Ninja (the latter is now the default)
        HS: Turn IREGI to off by default
        MZ: new NLO generation mode. It is more efficient from the memory and CPU point of
            view, in particular for high-multiplicity processes.
            Many thanks to Josh Bendavid for his fundamental contribution for this.
            The mode can be enabled with
            > set low_mem_multicore_nlo_generation True
            before generating the process.
        OM: Adding the possibility to use new syntax for tree-level processes:
            QED==2 and QCD>2: The first allows to select exactly a power of the coupling (at amplitude level
            While the second ask for a minimum value.
        RF: In the PDF uncertainty for fixed-order NLO runs, variations of alphaS were not included.
        OM: In MLM matching, fix a bug where the alpha_s reweighting was not fully applied on some events.
            (This was leading to effects smaller than the theoretical uncertainty)
        OM: Fixing the problem of using lhapdf6 on Mac
        MZ: Faster interface for LHAPDF6
        OM: Add support of epsilon_ijk in MadSpin
        OM: Fix multiple problem with multiparticles in MadSpin
        OM: Improve spinmode=None in MadSpin
        OM: Update the TopEffTh model
        MZ: Fix problem with slurm cluster
        OM: Improve scan functionalities
        PT: New way of handling Pythia8 decays
        RF: Fixed a bug that resulted in wrong event weights for NLO processes when requiring
            a very small number of events (introduced in 2.3.3)
        OM: Allow to keep the reweight information in the final lhe file for future computation
        MZ: updated FJcore to version 3.1.3 (was 3.0.5)

2.4.1 (09/06/16)
        OM: Fix a bug in fix target experiment with PDF on the particle at rest.
            The cross-section was correct but the z-boost was not performed correctly. (thanks D. Curtin)
        OM: Fix various bug in MadSpin
        OM: Fix some bug in MLM merging, where chcluster was forced to True (introduced in 2.2.0)
        OM: Allow to specify a path for a custom directory where to look for model via the environment
            variable PYTHONPATH. Note this used AFTER the standard ./models directory

2.4.2 (10/06/16)
        OM: fix a compilation problem for non standard gfortran system
        OM: reduce the need of lhapdf for standard LO run. (was making some run to test due to missing dependencies)