Log message:
benchmarks: Replace RMD160 checksums with BLAKE2s checksums

All checksums have been double-checked against existing RMD160 and
SHA512 hashes

Log message:
benchmarks: Remove SHA1 hashes for distfiles

Log message:
benchmarks/R-rbenchmark: import R-rbenchmark-1.0.0

rbenchmark is inspired by the Perl module Benchmark, and is intended
to facilitate benchmarking of arbitrary R code. The library consists
of just one function, benchmark, which is a simple wrapper around
system.time.  Given a specification of the benchmarking process
(counts of replications, evaluation environment) and an arbitrary
number of expressions, benchmark evaluates each of the expressions in
the specified environment, replicating the evaluation as many times as
specified, and returning the results conveniently wrapped into a data
frame.