devel/R-cran-bigmemory: New port

bigmemory provides the ability to create, store, access, and manipulate
massive matrices in R. Matrices are allocated to shared memory and may
use memory-mapped files.

Approved by: fuz (mentor)
Reviewed by: fuz (mentor), mat (previous revision)
Differential Revision: https://reviews.freebsd.org/D22677