Remove TwoPlayerRecovery. It means that if I'm failing and you're

passing, then I come back and you start failing, we keep going,
as long as one or the other of us was passing at any given time.

This is very unlikely to happen and be useful, and the fail logic
is complicated and brittle and needs simplification.

stepmania/src/ScreenGameplay.cpp

@@ -90,7 +90,6 @@ AutoScreenMessage( SM_BattleTrickLevel3 );
 static Preference<bool> g_bCenter1Player( "Center1Player", false );
 static Preference<bool> g_bShowLyrics( "ShowLyrics", true );
 static Preference<float> g_fNetStartOffset( "NetworkStartOffset", -3.0 );
-static Preference<bool> g_bTwoPlayerRecovery( "TwoPlayerRecovery", true );
 static Preference<bool> g_bEasterEggs( "EasterEggs", true );
 
 
@@ -1614,11 +1613,6 @@ void ScreenGameplay::Update( float fDeltaTime )
 			if( pi->GetPlayerStageStats()->bFailed )
 				continue; /* failed and is already dead */
 		
-			/* If recovery is enabled, only set fail if both are failing.
-			* There's no way to recover mid-song in battery mode. */
-			if( lt != SongOptions::LIFE_BATTERY && g_bTwoPlayerRecovery && !AllAreFailing() )
-				continue;
-
 			LOG->Trace("Player %d failed", (int)pn);
 			pi->GetPlayerStageStats()->bFailed = true;	// fail
 
@@ -2332,7 +2326,7 @@ void ScreenGameplay::HandleScreenMessage( const ScreenMessage SM )
 				pi->GetPlayerStageStats()->bFailed = true;
 			}
 
-			/* Mark failure.  This hasn't been done yet if g_bTwoPlayerRecovery is set. */
+			/* Mark failure. */
 			if( GAMESTATE->GetPlayerFailType(pi->GetPlayerState()) != SongOptions::FAIL_OFF &&
 				(pi->m_pLifeMeter && pi->m_pLifeMeter->IsFailing()) )
 				pi->GetPlayerStageStats()->bFailed = true;