Code review comment for lp:~maddevelopers/mg5amcnlo/v3_syntax_handler

Thanks Olivier!

I think it can be approved, bearing in mind that when using the old syntax QCD=X QED=Y

For the general user:

- fine, the code stops when it is required to do things with the old
syntax that are different to what one would expect from the 2018 paper.

For the expert user:

- if one types "set acknowledged_v3.1_syntax True --global" it is not
clear what is happening. Borns are produced for folders where they
should not be produced, real radiations are not present in folders where
I guess should also be present. Virtuals seems to be done correctly

Since it is not obvious how the code should behave for QCD=X QED=Y in the expert mode (it leads to a calculation of something that is not well defined) we can leave this issue open up to the moment when someone will need to use it.