Update boost to 1.71 and add asio

boost/date_time/time_defs.hpp

@@ -0,0 +1,43 @@
+#ifndef DATE_TIME_TIME_PRECISION_LIMITS_HPP
+#define DATE_TIME_TIME_PRECISION_LIMITS_HPP
+
+/* Copyright (c) 2002,2003 CrystalClear Software, Inc.
+ * Use, modification and distribution is subject to the 
+ * Boost Software License, Version 1.0. (See accompanying
+ * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
+ * Author: Jeff Garland 
+ * $Date$
+ */
+
+
+
+/*! \file time_defs.hpp 
+  This file contains nice definitions for handling the resoluion of various time
+  reprsentations.
+*/
+
+namespace boost {
+namespace date_time {
+
+  //!Defines some nice types for handling time level resolutions
+  enum time_resolutions {
+    sec,
+    tenth,
+    hundreth, // deprecated misspelled version of hundredth
+    hundredth = hundreth,
+    milli,
+    ten_thousandth,
+    micro,
+    nano,
+    NumResolutions
+  };
+
+  //! Flags for daylight savings or summer time
+  enum dst_flags {not_dst, is_dst, calculate};
+
+
+} } //namespace date_time
+
+
+
+#endif