Combine currr with furrr

[larry77]

Excellent project and very useful!
Often, to speed up computations I use furrr, see

https://github.com/DavisVaughan/furrr

which allows multicore operations with the map family.
If you could extend currr to work with furrr, it would be the jackpot since I would be able to run map in parallel and resume the computations at ease.
Keep up the good work.