resample_series: non-boot interface for resampling series
In rossklin/bootpan: Bootstrapping for panel data

Resample whole series from a time.table, disambiguating names if necessary (while retaining the types of each column).

1 2	resample_series(tt, num = NULL, resample = TRUE, new.index.name = "resample")

`tt`	`time.table` to resample from
`num`	number of series to resample (defaults to the same number as in `tt`)
`resample`	whether to sample with replacement (default)
`new.index.name`	name to use for additional index column (for disambigating separate resamples of the same data, defaults to "resample", set to NULL if new index is not to be included)