Log message:
Update to 0.19.4

Upstream changes:
0.19-4 Martyn Plummer <martyn.plummer@gmail.com>
	- Fix cumuplot, affected by changes in matplot in R 4.0.0.

Log message:
math: Replace RMD160 checksums with BLAKE2s checksums

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

Log message:
math: Remove SHA1 hashes for distfiles

Log message:
Update all R packages to canonical form.

The canonical form [1] of an R package Makefile includes the
following:

- The first stanza includes R_PKGNAME, R_PKGVER, PKGREVISION (as
  needed), and CATEGORIES.

- HOMEPAGE is not present but defined in math/R/Makefile.extension to
  refer to the CRAN web page describing the package.  Other relevant
  web pages are often linked from there via the URL field.

This updates all current R packages to this form, which will make
regular updates _much_ easier, especially using pkgtools/R2pkg.

[1] http://mail-index.netbsd.org/tech-pkg/2019/08/02/msg021711.html

Log message:
Remove MASTER_SITES= from individual R package Makefiles.

Each R package should include ../../math/R/Makefile.extension, which also
defines MASTER_SITES.  Consequently, it is redundant for the individual
packages to do the same.  Package-specific definitions also prevent
redefining MASTER_SITES in a single common place.

Log message:
math/R-coda: Import version 0.19.1

coda provides functions for summarizing and plotting the output from
Markov Chain Monte Carlo (MCMC) simulations, as well as diagnostic
tests of convergence to the equilibrium distribution of the Markov
chain.