Merge pull request #12 from jefferis/feature/clarify-os-arg-docs

Clarify the main purpose of the os argument
Depend on methods for sake of Rscript + S4

* closes #11
Merge pull request #13 from jefferis/fix/depend-methods

Depend on methods for sake of Rscript + S4
Add NEWS file
Version 0.3
Merge branch 'feature/cran-0.3' into pu

* feature/cran-0.3:
  Version 0.3
  Add NEWS file