predict_rlt_reg: Compute the prediction of a model built with 'rlt_reg'
In YohannLeFaou/sword: Random forest with IPC weights for survival analysis

Given a model built wtih rlt_reg, predict_rlt_reg allows to get the predictions of the model for new observations

1	predict_rlt_reg(obj, newdata)

`obj`	A list output by `rlt_reg`
`newdata`	A data.frame which contains the same variables as the ones used for the training

A list with the following elements :

`pred`	The vector of the predicted values for `phi`(T') (with T' = min(T, `max_time`)) for the observations of `newdata`
`surv`	The matrix which contains the estimated values of the survival curves at `time_points`, for the observations of `newdata`
`time_points`	The vector of the time points where the survival curves are evaluated