Corrections suggested by Yihui Xie <xie@yihui.name>.

git-svn-id: https://svn.r-project.org/R/trunk@66241 00db46b3-68df-0310-9c12-caf00c1e9a41
check for X11 libraries in X11() device and data editor/viewer

git-svn-id: https://svn.r-project.org/R/trunk@66242 00db46b3-68df-0310-9c12-caf00c1e9a41
update

git-svn-id: https://svn.r-project.org/R/trunk@66244 00db46b3-68df-0310-9c12-caf00c1e9a41
Updated.

git-svn-id: https://svn.r-project.org/R/trunk@66246 00db46b3-68df-0310-9c12-caf00c1e9a41
update

git-svn-id: https://svn.r-project.org/R/trunk@66247 00db46b3-68df-0310-9c12-caf00c1e9a41
a bit more on encodings

git-svn-id: https://svn.r-project.org/R/trunk@66248 00db46b3-68df-0310-9c12-caf00c1e9a41