GNU R general resampling infrastructure

 Classes and functions to create and summarize different types of
 resampling objects (e.g. bootstrap, cross-validation).
 .
 A resample is defined as the result of a two-way split of a data set.
 For example, when bootstrapping, one part of the resample is a sample
 with replacement of the original data. The other part of the split
 contains the instances that were not contained in the bootstrap sample.
 Cross-validation is another type of resampling.