Aurora IRC Client 0.8.3

Changed
- Per-network latency measurement refreshes every 15 seconds.
- Support email standardized as packages@greyline86.com.
- Check for Updates now reads Aurora version information from the official
  Greyline86 repository metadata at repo.greyline86.com.
- Added internationalization groundwork: saved language preference, English
  fallback, and localized User Guide directory layout.
- Updated User Guide for 0.8.3.

Regression control
- No unrelated IRC commands, logging behavior, fonts, layouts, network
  handling, or message rendering were intentionally changed.
