SimpleITK in CRAN or R-universe ?

[Artur-man]

A further thought on the potential cran microsite on github.
Assuming it is possible to generate binaries that are downloadable from
github, an alternative to the microsite is to create a "foyer" package on
cran, that redirects to the binaries. If we think that the binary
generation is reliable then a cran foyer package will provide more
visibility for SimpleITK than other R options. This idea is modelled after
some of the data packages on CRAN. It is a little roundabout, but you
install the foyer package, which then prompts the user to run a function
that would do the work - this could also provide options to use the current
installer, or redirect to the microcran option.

e.g.

.onAttach <- function(libname, pkgname) {
  packageStartupMessage("Run `installSimpleITK()` to fetch and install the
  full version of the package")
}

installSimpleITK <- function() {
  # figure out which version we should get
  rv <- R.Version()
  arch <- rv$arch
  os <- rv$os
  # etc
}

Originally posted by @richardbeare in #80