Remove translations with less then 500 strings

* packages/gen-kde-l10n.sh: Add filtering for translated counts.
General update.
* src/inst-kde-l10n.sh, src/uninst-kde-l10n.sh: Update
with results from gen-kde-l10n.sh.

This removes several translations but we might want to
limit it to even more complete translations. Kleopatra
has about 1800 strings.