Log Message:
Update to Prewikka 0.9.8. Changes:
- Save/load user configuration when using CGI authentication mode (#181).
- Show Prewikka version in the About page (#177).
- Use Python logging facility (available backend: stderr, file, smtp, syslog),
  multiple simultaneous handler supported (#113).
- Fix anonymous authentication.
- Fix external process going into zombie state (#178).
- Display correct alertident for invalid CorrelationAlert analyzerid/messageid pair.
- prewikka-httpd should now log the source address.
- Thread safety fixes.