Added a new argument rocpr.median = FALSE to the plot.btergmgof and lines.btergmgof functions to allow for the median curve instead of the mean curve. Added colored, transparent polygons around the curves when confint or stdev are used as rocpr.average options.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/btergm@35 edb9625f-4e0d-4859-8d74-9fd3b1da38cb