Port to use ki18n

This is a rebase of @drosca 's ki18n branch, to current master. I just tidied up the merge-conflicts and in one spot, chose to stick with a string that was in the repo, rather than changing the string (which would cause translation changes?). That was, um .. somethnig where .arg(QString::number(count) + QLatin1Char('.')) was used.

Since this has effects on translation, message extraction, etc., I think @jriddell and/or @aacid would have to look at it.