I chose filelight-17.* as it contains its own localizations (as obviously the one
shipped with the many years old kde4-l10n may not fit it anymore). However, it did
not occur to me, that this would conflict with l10n. "I'm stupid"++.
This now adds an EXTRACT_AFTER_ARGS to exclude the localization and a post-extract target to skip the build of filelights documentation for the kde-l10n ports that have it.