7534867: fix SSM crashes when selecting a song with only one player enabled
cddaab5: simplify SongUtil::GetStepsTypeAndDifficultyFromSortOrder
615aab0: add Style::GetUsesCenteredArrows (doubles + routine)
17f38e7: sanity check
[all code changes by Glenn Maynard]
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cleanup
small amount of work on guitar-five (still incomplete)
add more commented out stuff for replay data playback
debug trace combo in order to find out issues with smo-ssc
added old packet names as comments in NetworkSyncManager.h
AJ Kelly