Merge pull request #14 from kbroman/devel

Fix problems in scantwoF permutations
additive only = TURE as default
 bug fix in stepwiseqtlM.R
doc mismatch update (stepwiseqtlM additive.only=TRUE)
bug fix in refineqtlM.R
stepwiseqtlM.R
stepwiseqtlM test
vignette update
cvfold.R (crossvalidation to decide the number of basis to be used) update
cvfold man update, vignette update using cvfold
cvfold update
cvfold update
cvfold update
vig updqte
basis func nuber fix