use .C, etc. from R-2.15.2
update help file to reflect change to .C, etc. in R-2.15.2, but some editing
undo change to facilitate merge
Merge branch '21-scalars' into 22
Merge branch '21-dotcode' into 22
fixup, including bug in R-2.15.1, and subsequent
Merge branch '21-dotcode' into 22