increase dimensions and reduce white space in profile plots?

[iantaylor-NOAA]

Two trivial tweaks to the plots which helped for petrale:

1. Increasing the plot sizes from h = 7, w = 7 to h = 8, w = 8 in two places in profile_plot() made the figures more readable for petrale where there are lots of likelihood components overlapping and where the target and limit reference points are lower than for non-flatfish so the legend conflicts with the lines. Examples of the larger plots are in facilitate making profile and retro plots after manual changes to the models? #25. I don't know if all stocks would benefit from the larger size such that it should stay hardwired, or if it should be added as a user-controlled option.

2. White space can be reduced by changing

   nwfscDiag/R/profile_plot.R

   Line 92 in 8b4129e

   par(mfrow = panel)

   
   to par(mfrow = panel, mar = c(4, 4, 2, 2), oma = c(1, 1, 1, 1)) so that it matches
   

   nwfscDiag/R/profile_plot.R

   Line 153 in 8b4129e

   par(mfrow = c(2, 2), mar = c(4, 4, 2, 2), oma = c(1, 1, 1, 1))