Move quantile band drawing to separate fx
Remove mean.extinct argument
Simplify draw_qnts
Simplify sim line drawing
Remove default parameter
Use draw_means to draw mean lines
Clean up mean.lty processing
Fix bug in smoother
Clean up legend processing
Remove x arg for sim lines
Fix errors in plot.netdx examples
netdx sim lines and target lines colors consistent

If plots.joined = TRUE
Add mean lines to formation plots
Add mean lines for duration and dissolution plots
Add targ.line argument for toggle
Add quantile bands to plot.netdx
Update docs for new plotting functionality
Update news
Move plot utils into plot.R
Merge pull request #197 from statnet/plotdx

Updates to plot.netdx