initialize/destroy the cluster for each version (not only once per run)
added a thread that kills the 'pgxnclient check' command after a timeout (default: 300 seconds)
minor fixes and improvements (missing exception info, etc.)
the cluster is recreated for each tested version, but only when the PostgreSQL version is supported by the distribution
explicitly encoding all data (logs + diff) as utf-8 (hopefully this fixes the conversion errors)
probably a better way to deal with the unicode data (in regression diff)
added "--distribution" and "--version" options to quickly retest selected packages
encoding the logs/diff using base64 - this is messy (and I'd bet there's a better way), but seems to work