remove guitar cruft

There was a bunch of code for handling guitar-specific input such as hammer-ons/pull-offs and strumming. Given that guitar was removed, and as far as I understand, will not be added back into SM5, it makes sense to remove code that had no other use.

src/GameState.cpp

@@ -1188,7 +1188,6 @@ void GameState::ResetMusicStatistics()
 
 	FOREACH_PlayerNumber( p )
 	{
-		m_pPlayerState[p]->ClearHopoState();
 		m_pPlayerState[p]->m_Position.Reset();
 	}
 }