(p)dredge: warnings for arguments 'na.action' and 'marg.ex'
predict.gamm: new method
r.squaredGLMM.merMod: updated for binomial family models

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/mumin@301 edb9625f-4e0d-4859-8d74-9fd3b1da38cb