Audit translatable strings

[EbonJaeger]

We should audit all the translatable strings in eopkg to make sure that:

1. They are easy to translate
2. ngettext is used where appropriate for strings that need both a plural and singular form, e.g.:

   _("Adding %d packages to blah")

   Should be:

   ngetttext("Adding one package to blah", "Adding %d packages to blah", num_packages)

[ermo]

Ow.