updates for OS X 10.10 aka Yosemite

git-svn-id: https://svn.r-project.org/R/trunk@66784 00db46b3-68df-0310-9c12-caf00c1e9a41
revert rev 66773 -- not worth the hassle

git-svn-id: https://svn.r-project.org/R/trunk@66787 00db46b3-68df-0310-9c12-caf00c1e9a41
Eliminate _R_CHECK_RD_CONTENTS_AUTO_ and _R_CHECK_WARN_BAD_USAGE_LINES_.

git-svn-id: https://svn.r-project.org/R/trunk@66788 00db46b3-68df-0310-9c12-caf00c1e9a41