Fix deprecated usage of boost/bind.hpp.

boost/bind.hpp emits compiler warnings about deprecation of the header
and global _N placeholders. This commit converts usage of this header
to boost/bind/bind.hpp and using namespace boost::placeholders.

Where boost::bind is not actually used, the includes are removed.

test/adaptor_test/chained.cpp

@@ -19,7 +19,7 @@
 #include <boost/range/adaptor/transformed.hpp>
 #include <boost/range/adaptor/filtered.hpp>
 #include <boost/range/algorithm/copy.hpp>
-#include <boost/bind.hpp>
+#include <boost/bind/bind.hpp>
 
 #include <boost/test/test_tools.hpp>
 #include <boost/test/unit_test.hpp>
@@ -88,6 +88,8 @@ void chained_adaptors_test()
 
     std::set<foo> foos;
 
+    using namespace boost::placeholders;
+
     boost::copy(sep
         | boost::adaptors::transformed(boost::bind(&foo::from_string, _1))
         | boost::adaptors::filtered(boost::bind(&foo::is_valid, _1)),