Visualize Zuul's NNFI scheduler

Adds a subway map to the status page that reflects the current
proposed merge state according to Zuul's NNFI scheduler.

Makes the screen wider (1024 instead of 950 px) to accomodate
the additional width of the subway map.

Widen the graphs as well to match (also, evenly space them).

Change-Id: I11689c24c5d4aa58bb2dac3c595068e24af7e1d5
Merge "Visualize Zuul's NNFI scheduler"