Some clean up of R spkg

Imported from <a href="http://trac.sagemath.org/sage_trac/ticket/13443">trac #13443</a>.

Diff for the R spkg. For reference / review only.

Reported by: jdemeyer

Component: packages

CC: kcrisman

Report Upstream: N/A

Authors: Jeroen Demeyer

Dependencies: <a href="http://trac.sagemath.org/sage_trac/ticket/13348">trac #13348</a>, <a href="http://trac.sagemath.org/sage_trac/ticket/9906">trac #9906</a>

Work issues: 

Reviewers: Karl-Dieter Crisman, John Palmieri

Merged in: sage-5.4.beta2

Attachments: <ol><li><a href="http://trac.sagemath.org/sage_trac/attachment/ticket/13443/r-2.14.0.p6.diff">r-2.14.0.p6.diff: Diff for the R spkg. For reference / review only.</a> by jdemeyer at 20120910T15:32:33</li></ol>