Merge branch 'master' into 'master'

MLMMJ - Membership management

I think I'm close to the end of major works on this plugin...
I've implemented an interface to get simple list configuration, but using a lot of MLMMJ "TUNABLES". Anyway, there are a lot of unmanaged tunable yet. I wish to receive some feedbacks about what and how implement these. 
About the membership management: for now there is a minimal form, containing only list, name and mail of desired member. 

I think that from now, there will be a concrete (and better) alternative to mailman. I can improve a lot the whole system, but I think to be on the right way...what do you think about it?

See merge request !473