Feedback from Barb on cross section plots

[earajr]

Barb looked over the cross section plots and gave the following pointers:

• [x] Include units in lat / lon (degs north and east)
• [x] Sig figs in lat / lon (suggested 4 sig figs)
• [x] Ticks on X axis (suggested 10 majors including ends, nine minors)
• [x] Add gap between colourbar and plot
• [x] Label both axes
• [x] Simulation time and valid time to have same format, suggested: "YYYYMMDD hh:mm:ss"
• [x] Add gridlines to plot