[Rd] Small inaccuracy in the Writing R Extensions manual

[Berwin A Turlach]

G'day all,

In Chapter 1.4 (Writing package vignettes) the Writing R Extensions
manual states:

	By default @code{R CMD build} will run @code{Sweave} on all
	Sweave vignette source files in @file{vignettes}.  If
	@file{Makefile} is found in the vignette source directory, then
	@code{R CMD build} will try to run @command{make} after the
	@code{Sweave} runs, otherwise @code{texi2pdf} is run on each
	@file{.tex} file produced.

This does not seem to be quite correct as stated.  'R CMD build' seems
to run make only if there was a file in the directory vignettes that
Sweave successfully processed.   If the directory vignettes contains a
Makefile and subdirectories in which the actual vignettes are, 'R CMD
build' does not run make.

Cheers,

	Berwin