Version 1.29. Added gof.sienaAlgorithm() and various helper functions. Restructured the GOF function to make it work with the SIENA prediction function.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/btergm@30 edb9625f-4e0d-4859-8d74-9fd3b1da38cb