DoseFinding 1.2-1

• Documentation revised and updated, documentation now uses roxygen,
  README and NEWS (replacing old changelog) added
• Former "Depends" packages changed to "Imports"
• nlme added as suggested package
• Marius Thomas is the new maintainer of the package,
  Novartis Pharma AG added as copyright holder and funder
• Package is now hosted on https://github.com/openpharma/DoseFinding