[R-sig-dyn-mod] lsode vs ode15s; ok with radau

[Faelens Ruben]

> [...]Unfortunately, there is still a significant computational
difference:
> 
> ode15s: 35s
> radau: 1333s
> [...]

Please see
http://www.bioconductor.org/help/course-materials/2010/BioC2010/Efficien
tRProgramming.pdf for hints on efficient R programming. My model sped up
by a factor 5 by removing names from matrices and carefully looking at
which objects were duplicated.