Shrinkage t Statistic and Correlation-Adjusted t-Score

Implements the "shrinkage t" statistic introduced in Opgen-Rhein and Strimmer (2007) and a shrinkage estimate of the "correlation-adjusted t-score" (CAT score) described in Zuber and Strimmer (2009) . It also offers a convenient interface to a number of other regularized t-statistics commonly employed in high-dimensional case-control studies.