7 xy with mini aod

Update the code to 7XY.
--> I had to fix all the unused variables warning!
--> I've dropped for now the two pluggins (I'll add them back as soon as all the GetByLabel are replaced by GetByToken).  Even if in principle those are not needed anymore if we adopt the miniAOD strategy

IMPORTANT REMARK: 
Please try to limit the number of files in bin/ because it makes the maintenant quite painful.
I saw many files there that could be turned to simples root macro that can be located to your test/MyAnalysis directory.

Loic,