Skip glb-only plots for hemispheric ts

[forsyth2]

Follow up to #459 -- if a plot only uses glb data, with no option for hemispheric plotting, then it should not be plotted on the hemispheric time series.

[forsyth2]

@golaz @chengzhuzhang I found it most straightforward to leave the glb-only plots blank on the hemispheric time series pages. 1) It is very difficult to tell at the page setup level whether a plot will only have glb-data, 2) I think this actually looks better visually, as plots will be in the same row/col across all 3 (glb, n, s) for easy comparison.

Let me know if this is acceptable output/formatting:

glb:

n:

s:

[chengzhuzhang]

Hi Ryan, thanks for working on this. A small glitch: title of the temperature time-series plot for glb, N, S, all show global, it might be worth to fix..

[forsyth2]

Good catch, thanks @chengzhuzhang