Fix importer script problems exposed by importing the TranslateWiki.Net support page.
Already implemented in general (file tasks about specific issues if found, and not already present):
- Preserve content
- Preserve all subscriptions
- Preserve all thread summaries
- Preserve history of threads and summaries
- Preserve LQT logs for antivandalism purposes (history is preserved, other logs will remain in the logging table, but if logs are specifically an issue, we should file another task to investigate how accessible the old LQT logs would be with LQT not installed).