updated PreloadStore API

so that it is more clear that we are deleting preloaded data once read
keep French l10n up to date
Merge pull request #505 from ZogStriP/updated-preloadstore-api

updated PreloadStore API
Merge pull request #507 from ZogStriP/keep-french-l10n-up-to-date-3

keep French l10n up to date
slightly reduce read time req for trust level 1