Improve multi-engine support on Windows

SpadsUpdater.pm: 0.7
  . add optional "syncedSpringVersion" parameter to constructor, for Spring
    version dependent packages (Windows)
  . minor changes in log messages (Windows)

spads.pl: 0.11.13
  . remove old IRC bridge handling
  . cache Spring version returned by Unitsync
  . use Spring version dependent packages auto-update (Windows)

spadsInstaller.pl: 0.13
  . delay Spring server packages downloads and use unitsync to find which
    versions to download (Windows)

update.pl: 0.8
  . add replay upload scripts
  . add "springVersion" parameter for Spring server binaries updates
    (Windows)