First introduction of the HTML summary tab

At this stage, I did the bare minimum required to add one tab after
copy/pasting the ROOT example. Right now, it just adds a white page.
Working summary table

Not all collections are in. To be checked why.
Started to work on the summary plots

Investigated the way to add a tab with summary plots. A new class is in
place (dummy for now) to manage these plots.
Other small changes: use the status bar, clean the maxPt for MET (easier
to change later on), filter GenParticles on status==1.