shmootl: QTL Analysis Utilities for Yeast

This function makes an R/qtl cross - essentially a list of two elements named 'geno' and 'pheno' - from the input geno and pheno objects. Both input objects must have an 'info' attribute of class CrossInfo containing sample IDs. The output cross will be created from the intersection set of the samples in the input geno and pheno objects. Sample replicates in the input pheno object are preserved. Sample replicates in the input geno object must have identical genotypes, which will be replicated as needed to match the input phenotypes.