PriorityClassとThreadPriorityに関するオプションを追加

[SYSTEM]
PROCESSPRIORITY=REALTIME|HIGH|ABOVE_NORMAL|NORMAL|BELOW_NORMAL|IDLE
THREADPRIORITY_TSREADER=CRITICAL|HIGHEST|ABOVE_NORMAL|NORMAL|BELOW_NORMAL|LOWEST|IDLE
THREADPRIORITY_SENDER=CRITICAL|HIGHEST|ABOVE_NORMAL|NORMAL|BELOW_NORMAL|LOWEST|IDLE