PlotDetection for single roc point

@jklontz This allows us to use the non-confidence VJ output (i.e., `CascadeTransform` with `ROCMode=false`).  The plotting solution is to check if only a single ROC point exists in any of the files to be plotted, and, if so, plot using points instead of lines.

Ideally, we would only plot the files that have single points as points, and the other files with multiple points as lines. However, the way the .R output seems to be setup does not support this. So, for now at least, if any single file has only one ROC point, then all files are plotted as points.

Also, I looked into making this a user specified option, but that gets difficult b/c a variable number of input files are provided from the command line (making an optional point plot argument difficult).