devel/R-cran-parallelly: Add new port

Utility functions that enhance the 'parallel' package and support
the built-in parallel backends of the 'future' package. For example,
availableCores() gives the number of CPU cores available to your R
process as given by the operating system, 'cgroups' and Linux
containers, R options, and environment variables, including those
set by job schedulers on high-performance compute clusters. If none
is set, it will fall back to parallel::detectCores(). Another example
is makeClusterPSOCK(), which is backward compatible with
parallel::makePSOCKcluster() while doing a better job in setting
up remote cluster workers without the need for configuring the
firewall to do port-forwarding to your local computer.

WWW: https://cran.r-project.org/web/packages/parallelly/