FIX for CRAN - Use {parallel} for parallel processing

[MikeKSmith]

(May already be fixed, but let's double check)

---

R 2.14.0 (18 months ago) introduced package 'parallel', and using
doParallel will generally give your users (including the CRAN check
farm) a better experience that doSNOW. But your packages are still
using doSNOW (for MSToolkit in preference to doParallel, and for
diverSity oddly on Linux only!)

Can we please have versions with

Depends: R (>= 2.14)

and making use of doParallel rather than doSNOW.