Parsing and evaluation tools that make it easy to recreate the command
line behaviour of R.
Note: this commit is part of reorganizing some of the recently
imported R packages, which are being reimported into more appropriate
categories (and removed from math) as a result of a recent discussion
on tech-pkg and privately with wiz@. See the thread starting with:
http://mail-index.netbsd.org/tech-pkg/2014/09/05/msg013558.html