a4d04ebece
In logarithmic plots it is not easy to spot which event are longer than 60 seconds. A thin grey line help with this. Also: fixed the marker lines (zoom area) which broke when y-ranges were introduced. The lines were not drawn correctly, when the y-axis offset was greater than 0. Gnuplot supports differen coordinate systems. 'graph' is relative to the area within the axes, 0,0 is bottom left and 1,1 is top right. And 'first' is based on the values of the x1 axis. By using "graph 0.25,0" we say that the starting point is 25% of the x-axis and 0% of the y-axis without having to compute the exact values.