New version to make sienaRI.Rd() operational (I hope!). Also incorporation of some other changes: to sienaBayes, to have the option of centering dyadic covariates, and some other small things - see the changeLog.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rsiena@269 edb9625f-4e0d-4859-8d74-9fd3b1da38cb