cleanup low-level time handling: only make adjustments to the clock that

the arch really needs; Unix gettimeofday does not loop like Win32 timeGetTime
so don't mess with it

stepmania/src/arch/ArchHooks/ArchHooks_Unix.cpp

@@ -143,7 +143,10 @@ static int64_t GetMicrosecondsSinceEpoch()
 int64_t ArchHooks::GetMicrosecondsSinceStart( bool bAccurate )
 {
 	static int64_t iStartTime = GetMicrosecondsSinceEpoch();
-	return GetMicrosecondsSinceEpoch() - iStartTime;
+	int64_t ret = GetMicrosecondsSinceEpoch() - iStartTime;
+	if( bAccurate )
+		ret = FixupTimeIfBackwards( ret );
+	return ret;
 }
 
 /*

stepmania/src/arch/ArchHooks/ArchHooks_Win32.cpp

@@ -203,7 +203,14 @@ int64_t ArchHooks::GetMicrosecondsSinceStart( bool bAccurate )
 	if( !g_bTimerInitialized )
 		InitTimer();
 
-	return (timeGetTime() - g_iStartTime) * 1000;
+	int64_t ret = (timeGetTime() - g_iStartTime) * int64_t(1000);
+	if( bAccurate )
+	{
+		ret = FixupTimeIfLooped( ret );
+		ret = FixupTimeIfBackwards( ret );
+	}
+	
+	return ret;
 }
 
 /*

stepmania/src/arch/ArchHooks/ArchHooks_Xbox.cpp

@@ -19,7 +19,14 @@ int64_t ArchHooks::GetMicrosecondsSinceStart( bool bAccurate )
 	if( !g_bTimerInitialized )
 		InitTimer();
 
-	return (timeGetTime() - g_iStartTime) * 1000;
+	int64_t ret = (timeGetTime() - g_iStartTime) * int64_t(1000);
+	if( bAccurate )
+	{
+		ret = FixupTimeIfLooped( ret );
+		ret = FixupTimeIfBackwards( ret );
+	}
+	
+	return ret;
 }
 
 ArchHooks_Xbox::ArchHooks_Xbox()

stepmania/src/arch/ArchHooks/ArchHooks_darwin.cpp

@@ -298,7 +298,10 @@ static int64_t GetMicrosecondsSinceEpoch()
 int64_t ArchHooks::GetMicrosecondsSinceStart( bool bAccurate )
 {
 	static int64_t iStartTime = GetMicrosecondsSinceEpoch();
-	return GetMicrosecondsSinceEpoch() - iStartTime;
+	int64_t ret = GetMicrosecondsSinceEpoch() - iStartTime;
+	if( bAccurate )
+		ret = FixupTimeIfBackwards( ret );
+	return ret;
 }
 
 /*