merged boost 1.34 fix from 0.12rc branch

bindings/python/src/datetime.cpp

@@ -5,9 +5,12 @@
 #include <boost/python.hpp>
 #include <boost/date_time/posix_time/posix_time_types.hpp>
 #include "optional.hpp"
+#include <boost/version.hpp>
 
 using namespace boost::python;
 
+#if BOOST_VERSION < 103400
+
 // From Boost 1.34
 object import(str name)
 {
@@ -17,6 +20,8 @@ object import(str name)
     return object(module);
 }
 
+#endif
+
 object datetime_timedelta;
 object datetime_datetime;