update comments

git-svn-id: https://svn.r-project.org/R/trunk@66820 00db46b3-68df-0310-9c12-caf00c1e9a41
remove download.file(method = "lynx")

git-svn-id: https://svn.r-project.org/R/trunk@66822 00db46b3-68df-0310-9c12-caf00c1e9a41
correction: there are two separate methods

git-svn-id: https://svn.r-project.org/R/trunk@66823 00db46b3-68df-0310-9c12-caf00c1e9a41