haz_costum: costumized intensity
In niklasmaltzahn/multistate: simulation and estimation of multistate models

This function can build constomized intensity functions based on splies

1	haz_costum(initial_grid, grid_length, method, ...)

`initial_grid`	A two column matrix of time points and hazard values.
`grid_length`	Grid resolution in spline approximation.
`method`	Spline method.
`plot`	If True a plot of the specified hazard is generated. Default is False.
`type`	Character specifying to output hazard function "haz" or cumulative hazard function "cumhaz".

##---- Should be DIRECTLY executable !! ----
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function (x)
{
  }