adding a checkbox to add the right timezone and locales

If you take a look at this recipe you will see that there is two sections to fix the timezone and the locales in the recipe. One is generic; we should be able to add it easily:

  # Timezone and locales settings
  TZ=Europe/Paris
  ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
  #dpkg-reconfigure -f noninteractive tzdata
  sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen
  locale-gen
  echo 'LANG="en_US.UTF-8' >> /etc/default/locale

The other one is specific to R and is done later in the recipe:

  ## fixing locales in R
  #echo 'LANG <- Sys.getenv("LANG")' | R --slave
  #echo 'Sys.setlocale("LC_ALL", LANG)' | R --slave

This would be a nice enhancement in wicopa