Version 3.4.0

• New: Suite of tools for additive modeling, most notably expand_spline() and plot_spline() (thank you to Ryan Kurth for her work on this project)
• New: grpreg() now returns linear.predictors object
• New: grpreg() and grpsurv() now have residuals() methods
• New: predict.grpsurv() can now predict cumulative hazard (type="hazard")
• New: Can now perform cross-validation with group bridge in cv.grpreg()
• Changed: fit$y now returns original y, not centered y
• Changed: grpsurv() now consistent with grpreg() in terms of returning deviance (2*loss) and groups as factors
• Fixed: predict() no longer converts factors to strings if type="groups"
• Fixed: grpsurv() works correctly if a single feature is supplied