Fix bathyleg overplotting when using small(ish) image sizes.

[raymondben]

You can tweak the plotargs in a SOmap object directly. As yet none of this is documented, because (amongst other reasons) none of it is final and therefore may change. But something like:

p <- SOmap()
p$bathy_legend$plotargs$labels$adj <- 0
p

or whatever parm you need to tweak.

[Maschette]

Yep this is me being an idiot and forgetting things exist. I will leave this issue up to remind myself to write some documentation