[Rd] Vignettes and CRAN checks

[Terry Therneau]

I'l like to chime in on the subject of vignette checks.
I have one vignette in the coxme library that would be better described 
as a white paper. It discusses the adequacy of the Laplace transform 
under various scenarios.  It contains some substantial computations, so 
I'd like to mark it as "never ever run this" for both CRAN and my local 
builds, my next update of it will turn it into a 30+ minute 
compuatation.  Almost all users will need only the pdf;  however, my 
master file for creating it is .Rnw form and I'd like to make it 
available to those who might want to dig deeper.  I (and every other 
program I know of) had always assumed that the Laplace approx was 
excellent for a mixed effects Cox model, I'm finding out that that there 
are a few cases where this isn't so.  Luckily only a few, but this is 
important documentation.

I also have more conventional vignettes of the "how to use this package" 
variety, the standard CRAN check process for those is both welcome and 
appropriate.

Terry T.