florium: German and English

Every domain has its own language (SITE/LANGUAGE): texts, BB code labels,
dates and mails. The administration has ADMIN/LANGUAGE, the setup wizard
follows the browser. Texts go through loc(), English in share/i18n/en.tsv,
tools/i18n_keys.py --missing checks the coverage. formatDate() instead of
cutting formatTime().

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>