[Rd] simplifying number of R installations on disk

[Charlotte Maia]

I think it's a very bad idea to truncate version numbers.
Version numbers are important, and there may be a critical difference
x.y.0 and x.y.1.
Plus there is no guarantee that the updated version is better than the
previous one.
Hence a programmer may need to go back to x.y.0 until x.y.2 is released.

Perhaps there should be an option somewhere to remove existing
installations (maybe there is????), however by default, installing a
new version of a programming language, should not uninstall existing
versions.


-- 
Charlotte Maia
Open Source Developer and Statistician
http://sites.google.com/site/maiagx