Commit
              ae681935179f62ffb588fe2aab7c95780034f153
              by Vince LarsonAdd 3 new features to dashboard:
1) Add Huber (confusingly called "Ransac") regressor to find
a fit that de-weights outliers.  The goal is to identify tuning trade-offs.
2) Add ElasticNet regressor.  The goal here is to obtain
a good fit that doesn't perturb the parameters too much,
and that leaves some parameter values unchanged if possible.
3) Add a routine to create PCA biplots.  The goal here
is to identify outliers (i.e., tuning trade-offs) analytically.
For #910.