Replace SAFE_DELETE / SAFE_DELETE_ARRAY macros

SAFE_DELETE -> RageUtil::SafeDelete
SAFE_DELETE_ARRAY -> RageUtil::SafeDeleteArray

Update JsonUtil.h to include RageUtil.h - MSVC doesn't need it included for some reason, but GCC and XCode does.

src/RageThreads.cpp

@@ -80,7 +80,7 @@ struct ThreadSlot
 
 	void Release()
 	{
-		SAFE_DELETE( m_pImpl );
+		RageUtil::SafeDelete( m_pImpl );
 		Init();
 	}